fix(core): give the kernel-keyring unlock owner read access

A new key grants its owner only "view"; read needs possession, which a process has only when its session keyring links to the user keyring. A systemd user service or a container does not guarantee that, so the daemon could store the unlock and then fail to read it back (EACCES). Set the permissions explicitly after add_key.
feat(core,cli,gui): support two-password accounts without storing the mailbox password
2026-11-03 16:41:26 +01:00 · 2026-10-07 08:17:50 +02:00 · 2026-10-07 08:17:50 +02:00 · 2026-10-07 08:17:50 +02:00 · 2026-10-07 04:27:22 +02:00 · 2026-10-06 19:29:02 +02:00
119 changed files with 35667 additions and 9916 deletions
@@ -67,7 +67,13 @@ jobs:
            User aur
          EOF
          # Pin the host key to the fingerprint published on aur.archlinux.org.
-          ssh-keyscan -t ed25519 aur.archlinux.org > "$HOME/.ssh/known_hosts"
+          # The scan sometimes returns nothing from the runner, so retry it.
+          for attempt in 1 2 3 4 5; do
+            ssh-keyscan -T 15 -t ed25519 aur.archlinux.org > "$HOME/.ssh/known_hosts" &&
+              [ -s "$HOME/.ssh/known_hosts" ] && break
+            echo "ssh-keyscan attempt $attempt returned no key; retrying"
+            sleep 10
+          done
          ssh-keygen -lf "$HOME/.ssh/known_hosts" | grep -q 'SHA256:RFzBCUItH9LZS0cKB5UE6ceAYhBD5C8GeOBip8Z11+4'
          chown -R builder: "$HOME/.ssh"
          chmod 600 "$HOME/.ssh/aur"
@@ -32,8 +32,14 @@ jobs:
        with:
          toolchain: '1.96'
          components: rustfmt, clippy
+          cache: false

+      # Tags can only restore caches saved on main, so only main saves one. The
+      # release workflow restores this key for its quality gates.
      - uses: swatinem/rust-cache@v2
+        with:
+          shared-key: debug
+          save-if: ${{ github.ref == 'refs/heads/main' }}

      - name: Formatting
        run: cargo fmt --all -- --check
@@ -57,3 +63,84 @@ jobs:

  # Real Proton credentials and /dev/fuse deliberately do not run on pull
  # requests. Follow docs/TESTING.md on a dedicated test-account runner.
+
+  # The seeded simulation runs (docs/TESTING.md): real FUSE
+  # daemons against an in-memory Drive, so they need /dev/fuse but no account.
+  simulation:
+    if: github.event_name != 'pull_request'
+    runs-on: ubuntu-24.04
+    timeout-minutes: 30
+
+    steps:
+      - uses: actions/checkout@v7
+
+      - name: Install native dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y \
+            pkg-config \
+            fuse3 \
+            libfuse3-dev \
+            libgtk-4-dev \
+            libadwaita-1-dev \
+            libwebkitgtk-6.0-dev \
+            libsecret-1-dev \
+            libdbus-1-dev
+
+      - name: Install minimum supported Rust
+        uses: actions-rust-lang/setup-rust-toolchain@v1
+        with:
+          toolchain: '1.96'
+          cache: false
+
+      - uses: swatinem/rust-cache@v2
+        with:
+          shared-key: debug
+          save-if: false
+
+      - name: Simulation runs
+        run: 'cargo test -p pdfs-fuse --lib --locked sim:: -- --ignored --test-threads=1'
+
+      # A hung step writes every daemon thread's stack next to the run's
+      # state; without them a hang that does not replay cannot be told apart.
+      - name: Keep the stacks of a hung run
+        if: failure()
+        uses: actions/upload-artifact@v7
+        with:
+          name: simulation-stacks
+          path: /tmp/pdfs-sim-*/stacks.txt
+          if-no-files-found: ignore
+
+  # Keeps the release-profile dependencies cached on main, where the release
+  # workflow can restore them; a tag cannot reuse the caches of earlier tags.
+  release-cache:
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+    runs-on: ubuntu-24.04
+
+    steps:
+      - uses: actions/checkout@v7
+
+      - name: Install native dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y \
+            pkg-config \
+            libfuse3-dev \
+            libgtk-4-dev \
+            libadwaita-1-dev \
+            libwebkitgtk-6.0-dev \
+            libsecret-1-dev \
+            libdbus-1-dev
+
+      - name: Install minimum supported Rust
+        uses: actions-rust-lang/setup-rust-toolchain@v1
+        with:
+          toolchain: '1.96'
+          cache: false
+
+      - uses: swatinem/rust-cache@v2
+        with:
+          shared-key: release
+
+      - name: Release build
+        run: cargo build --release --locked
@@ -10,8 +10,60 @@ permissions:
  contents: write

 jobs:
+  checks:
+    name: Release quality gates
+    runs-on: ubuntu-24.04
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v7
+
+      - name: Install system dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y \
+            pkg-config \
+            libfuse3-dev \
+            libgtk-4-dev \
+            libadwaita-1-dev \
+            libwebkitgtk-6.0-dev \
+            libsecret-1-dev \
+            libdbus-1-dev
+
+      - name: Set up Rust
+        uses: actions-rust-lang/setup-rust-toolchain@v1
+        with:
+          toolchain: '1.96'
+          components: rustfmt, clippy
+          cache: false
+
+      # A tag can read the caches of main but its own caches are useless to the next
+      # tag, so this only restores what CI saved on main.
+      - name: Cache Cargo target
+        uses: swatinem/rust-cache@v2
+        with:
+          shared-key: debug
+          save-if: false
+
+      - name: Verify tag and manifest versions
+        if: startsWith(github.ref, 'refs/tags/')
+        shell: bash
+        run: |
+          tag_version="${GITHUB_REF_NAME#v}"
+          manifest_version="$(sed -n 's/^version = "\([^"]*\)"/\1/p' Cargo.toml | head -n1)"
+          pkgbuild_version="$(sed -n 's/^pkgver=//p' packaging/PKGBUILD | head -n1)"
+          test "$tag_version" = "$manifest_version"
+          test "$tag_version" = "$pkgbuild_version"
+
+      - name: Release quality gates
+        run: |
+          cargo fmt --all -- --check
+          cargo clippy --workspace --all-targets -- -D warnings
+          cargo test --workspace --locked
+          scripts/fuse-acceptance.sh --offline-only
+
  build-release:
-    name: Build and Release
+    name: Build packages
    runs-on: ubuntu-24.04
    environment: 'rpm signing'

@@ -38,27 +90,14 @@ jobs:
        uses: actions-rust-lang/setup-rust-toolchain@v1
        with:
          toolchain: '1.96'
-          components: rustfmt, clippy
+          cache: false

+      # Restores the release-profile dependencies that CI builds on main.
      - name: Cache Cargo target
        uses: swatinem/rust-cache@v2
-
-      - name: Verify tag and manifest versions
-        if: startsWith(github.ref, 'refs/tags/')
-        shell: bash
-        run: |
-          tag_version="${GITHUB_REF_NAME#v}"
-          manifest_version="$(sed -n 's/^version = "\([^"]*\)"/\1/p' Cargo.toml | head -n1)"
-          pkgbuild_version="$(sed -n 's/^pkgver=//p' packaging/PKGBUILD | head -n1)"
-          test "$tag_version" = "$manifest_version"
-          test "$tag_version" = "$pkgbuild_version"
-
-      - name: Release quality gates
-        run: |
-          cargo fmt --all -- --check
-          cargo clippy --workspace --all-targets -- -D warnings
-          cargo test --workspace --locked
-          scripts/fuse-acceptance.sh --offline-only
+        with:
+          shared-key: release
+          save-if: false

      - name: Build release binaries
        run: |
@@ -127,7 +166,7 @@ jobs:
          Maintainer: Nils Pukropp <contact@narl.io>
          Depends: fuse3, libgtk-4-1 (>= 4.12.0), libadwaita-1-0 (>= 1.5.0), libsecret-1-0, libwebkitgtk-6.0-4, libimage-exiftool-perl
          Installed-Size: ${INSTALLED_SIZE}
-          Homepage: https://github.com/narrrl/proton-drive-linux
+          Homepage: https://proton-drive.narl.io
          Description: Unofficial Proton Drive client for Linux
           Files-on-demand Proton Drive for the Linux desktop, unaffiliated with Proton AG:
           - FUSE virtual mount with block-level caching
@@ -152,6 +191,7 @@ jobs:
            --define "_topdir $PWD/rpmbuild" \
            --define "_sourcedir $PWD" \
            --define "git_dir $PWD" \
+            --define "prebuilt 1" \
            --define "version ${RPM_VERSION}" \
            --define "_dbpath $PWD/rpmbuild/db" \
            packaging/proton-drive-linux.spec
@@ -190,8 +230,19 @@ jobs:
            *.rpm
          if-no-files-found: error

+  publish:
+    name: Create GitHub Release
+    needs: [checks, build-release]
+    if: startsWith(github.ref, 'refs/tags/')
+    runs-on: ubuntu-24.04
+
+    steps:
+      - name: Download packages
+        uses: actions/download-artifact@v8
+        with:
+          name: proton-drive-linux-builds
+
      - name: Create GitHub Release
-        if: startsWith(github.ref, 'refs/tags/')
        uses: softprops/action-gh-release@v3
        with:
          files: |
@@ -205,7 +256,7 @@ jobs:

  aur:
    name: Publish AUR packages
-    needs: build-release
+    needs: publish
    if: startsWith(github.ref, 'refs/tags/')
    uses: ./.github/workflows/aur.yml
    with:
@@ -0,0 +1,121 @@
+name: Test build
+
+# On-demand Fedora RPM of any branch, for someone to try a fix before it ships.
+# Run it from the Actions tab ("Run workflow", pick the branch). Built inside a
+# Fedora container so the binaries link against Fedora's own GTK, libadwaita and
+# WebKitGTK, not the Ubuntu ones the release RPM is built against.
+#
+# The RPM is unsigned and versioned `<Cargo version>-1.test.<sha>`, so it sorts
+# below the release it precedes and `dnf` replaces it when that ships.
+on:
+  workflow_dispatch:
+    inputs:
+      fedora:
+        description: 'Fedora release to build on'
+        required: false
+        default: '44'
+        type: string
+      prerelease:
+        description: 'Also publish a pre-release anyone can download without a GitHub login'
+        required: false
+        default: false
+        type: boolean
+
+permissions:
+  contents: read
+
+concurrency:
+  group: test-build-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  rpm:
+    name: Fedora ${{ inputs.fedora }} RPM
+    runs-on: ubuntu-24.04
+    container: fedora:${{ inputs.fedora }}
+    steps:
+      - name: Install build dependencies
+        run: |
+          dnf install -y --setopt=install_weak_deps=False \
+            git rpm-build gcc gcc-c++ make gettext curl \
+            pkgconf-pkg-config fuse3-devel gtk4-devel libadwaita-devel \
+            libsecret-devel dbus-devel glib2-devel webkitgtk6.0-devel
+
+      - name: Checkout repository
+        uses: actions/checkout@v7
+
+      # Fedora's packaged Rust can trail the workspace's minimum (1.96).
+      - name: Set up Rust
+        uses: actions-rust-lang/setup-rust-toolchain@v1
+        with:
+          toolchain: '1.96'
+          cache: false
+
+      - name: Cache Cargo target
+        uses: swatinem/rust-cache@v2
+        with:
+          shared-key: fedora-test-build
+          save-if: false
+
+      - name: Build release binaries
+        run: cargo build --release --locked
+
+      - name: Package RPM
+        run: |
+          git config --global --add safe.directory "$GITHUB_WORKSPACE"
+          VERSION=$(grep -m1 '^version' Cargo.toml | cut -d'"' -f2)
+          SHORT=${GITHUB_SHA::7}
+          mkdir -p rpmbuild/{BUILD,RPMS,SOURCES,SPECS,SRPMS,BUILDROOT,db}
+          rpmbuild -bb \
+            --nodeps \
+            --define "_topdir $PWD/rpmbuild" \
+            --define "_sourcedir $PWD" \
+            --define "git_dir $PWD" \
+            --define "prebuilt 1" \
+            --define "version ${VERSION}" \
+            --define "dist .test.${SHORT}" \
+            --define "_dbpath $PWD/rpmbuild/db" \
+            packaging/proton-drive-linux.spec
+          mkdir -p out
+          cp rpmbuild/RPMS/x86_64/*.rpm out/
+          # The bare binaries, for trying one without installing anything.
+          tar -czf "out/proton-drive-linux-${VERSION}-${SHORT}-fedora${{ inputs.fedora }}-x86_64.tar.gz" \
+            -C target/release pdfs pdfs-tray pdfs-app pdfs-prompt
+          ls -l out
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v7
+        with:
+          name: proton-drive-linux-fedora${{ inputs.fedora }}-${{ github.sha }}
+          path: out/*
+          retention-days: 14
+          if-no-files-found: error
+
+  prerelease:
+    name: Publish pre-release
+    needs: rpm
+    if: inputs.prerelease
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: write
+    steps:
+      - name: Download build
+        uses: actions/download-artifact@v8
+        with:
+          path: out
+          merge-multiple: true
+
+      # One rolling pre-release per branch: a new run replaces the last one, so
+      # the link a tester was given keeps pointing at the newest build.
+      - name: Publish
+        env:
+          GH_TOKEN: ${{ github.token }}
+          GH_REPO: ${{ github.repository }}
+        run: |
+          TAG="test-$(echo "${GITHUB_REF_NAME}" | tr -c 'A-Za-z0-9._\n' '-')"
+          gh release delete "$TAG" --cleanup-tag --yes 2>/dev/null || true
+          gh release create "$TAG" out/* \
+            --target "$GITHUB_SHA" \
+            --prerelease \
+            --title "Test build of ${GITHUB_REF_NAME} (${GITHUB_SHA::7})" \
+            --notes "Unsigned test build of branch \`${GITHUB_REF_NAME}\` at ${GITHUB_SHA}. Not a release; replaced by the next test build of this branch."
@@ -39,9 +39,9 @@ cargo test --workspace --locked
 scripts/fuse-acceptance.sh --offline-only
 ```

-Changes to the FUSE layer, sync, or the pending-operation queue should also be exercised against a
-real mount before review — see [`docs/TESTING.md`](docs/TESTING.md). Live runs are destructive:
-use a dedicated test account, never one holding data you cannot lose.
+Changes to the FUSE layer, sync, or the queue should also pass the simulation runs and be
+exercised against a real mount before review — see [`docs/TESTING.md`](docs/TESTING.md). Live
+runs are destructive: use a dedicated test account, never one holding data you cannot lose.

 ## Making changes

@@ -3474,7 +3474,7 @@ checksum = "2ee67f1008b1ba2321834326597b8e186293b049a023cdef258527550b9935b4"

 [[package]]
 name = "pdfs-cli"
-version = "2.6.0"
+version = "3.1.0"
 dependencies = [
 "anyhow",
 "clap",
@@ -3485,13 +3485,15 @@ dependencies = [
 "tokio",
 "tracing",
 "tracing-subscriber",
+ "zeroize",
 ]

 [[package]]
 name = "pdfs-core"
-version = "2.6.0"
+version = "3.1.0"
 dependencies = [
 "async-trait",
+ "base64 0.23.1",
 "dbus-secret-service-keyring-store",
 "directories",
 "ignore",
@@ -3508,13 +3510,15 @@ dependencies = [
 "thiserror 2.0.20",
 "tokio",
 "tracing",
+ "zeroize",
 "zip",
 ]

 [[package]]
 name = "pdfs-fuse"
-version = "2.6.0"
+version = "3.1.0"
 dependencies = [
+ "async-trait",
 "base64 0.23.1",
 "fuser",
 "futures",
@@ -3528,12 +3532,13 @@ dependencies = [
 "sha1 0.11.0",
 "tokio",
 "tracing",
+ "tracing-subscriber",
 "zip",
 ]

 [[package]]
 name = "pdfs-gui"
-version = "2.6.0"
+version = "3.1.0"
 dependencies = [
 "anyhow",
 "async-channel",
@@ -3570,9 +3575,9 @@ checksum = "9b4f627cb1b25917193a259e49bdad08f671f8d9708acfd5fe0a8c1455d87220"

 [[package]]
 name = "pgp"
-version = "0.20.0"
+version = "0.21.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1cfa4743b28656065ff4c0ba09e46b357a65e8c00fc2341e89084b82f87cbdf1"
+checksum = "ae70f4d9325a391db30d115d6191a7bb67cec856aa0bba131290f0c4e09a532a"
 dependencies = [
 "aead 0.5.2",
 "aes 0.8.4",
@@ -3773,9 +3778,9 @@ dependencies = [

 [[package]]
 name = "proton-drive-rs"
-version = "0.7.0"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d0f6996724e51e99f03d2843828de9477afc39baa764403cb69490cabc1c4d93"
+checksum = "5bde475139afb5fc2649621e1d283e243f9df2bb412f08802cdf3f4ffaf97c44"
 dependencies = [
 "async-trait",
 "base64 0.23.1",
@@ -3800,9 +3805,9 @@ dependencies = [

 [[package]]
 name = "proton-sdk"
-version = "0.7.0"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "91cc25654133bd5714407a1df0996eaf214a6e8e0bb95d8139bc42e7cee31c34"
+checksum = "faf32d0a03f7d13bd9bdcc8c9503e35e9df9318ca9f2a100dcf06cf50cb7ac8c"
 dependencies = [
 "aes-gcm 0.11.1",
 "async-trait",
@@ -3829,6 +3834,7 @@ dependencies = [
 "thiserror 2.0.20",
 "tokio",
 "tracing",
+ "zeroize",
 ]

 [[package]]
@@ -3,20 +3,20 @@ resolver = "2"
 members = ["crates/pdfs-core", "crates/pdfs-fuse", "crates/pdfs-cli", "crates/pdfs-gui"]

 [workspace.package]
-version = "2.6.0"
+version = "3.1.0"
 edition = "2024"
 license = "MIT"
 authors = ["Nils Pukropp <contact@narl.io>"]
 rust-version = "1.96"
 repository = "https://github.com/narrrl/proton-drive-linux"
-homepage = "https://github.com/narrrl/proton-drive-linux"
+homepage = "https://proton-drive.narl.io"
 readme = "README.md"
 keywords = ["proton", "drive", "fuse", "sync", "linux"]
 categories = ["filesystem", "command-line-utilities"]

 [workspace.dependencies]
-proton-sdk = { version = "0.7.0" }
-proton-drive-rs = { version = "0.7.0" }
+proton-sdk = { version = "0.8.0" }
+proton-drive-rs = { version = "0.8.0" }

 # Internal crates.
 pdfs-core = { path = "crates/pdfs-core" }
@@ -26,6 +26,7 @@ tokio = { version = "1", features = ["rt-multi-thread", "macros", "sync", "fs",
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 base64 = "0.23"
+zeroize = "1"
 thiserror = "2"
 anyhow = "1"
 # Non-poisoning mutexes. A handler that panics while holding a lock must not
@@ -8,11 +8,14 @@
 local folders, Photos, sharing, and a native GTK4 app with tray and search launcher, plus a
 scriptable CLI.

+**[proton-drive.narl.io](https://proton-drive.narl.io)**
+
 [![CI](https://github.com/narrrl/proton-drive-linux/actions/workflows/ci.yml/badge.svg)](https://github.com/narrrl/proton-drive-linux/actions/workflows/ci.yml)
 [![Release](https://img.shields.io/github/v/release/narrrl/proton-drive-linux?sort=semver)](https://github.com/narrrl/proton-drive-linux/releases/latest)
 [![AUR](https://img.shields.io/aur/version/proton-drive-for-linux)](https://aur.archlinux.org/packages/proton-drive-for-linux)
 [![License: MIT](https://img.shields.io/badge/license-MIT-blue.svg)](LICENSE)
 [![Rust 1.96+](https://img.shields.io/badge/rust-1.96%2B-orange.svg)](https://www.rust-lang.org)
+[![Buy me a coffee](https://img.shields.io/badge/Buy%20me%20a%20coffee-FFDD00?logo=buymeacoffee&logoColor=black)](https://buymeacoffee.com/narl)

 <img src="images/files.png" alt="My files in the Proton Drive app" width="820">

@@ -36,8 +39,9 @@ scriptable CLI.
 - **Synced folders.** Back up folders such as `~/Documents` under your computer in Proton Drive,
  as a full two-way copy or online only. Gitignore-style `.pdfsignore` rules, conflict copies
  instead of overwrites, pause and bandwidth limits.
- **Safe writes.** Changes are staged on disk and queued before they are acknowledged, so they
-  survive a lost connection, a crash or a reboot and upload when they can.
+- **Works at local speed.** Making, renaming and deleting files and folders returns at once, online
+  or offline. Changes are staged on disk and queued before they are acknowledged, so they survive
+  a lost connection, a crash or a reboot and reach Drive when they can.

 **Desktop app**

@@ -48,7 +52,8 @@ scriptable CLI.
 - **Sharing.** Invite people as viewer, editor or admin, create public links with password and
  expiry, accept invitations.
 - **Sync overview.** What is uploading, what is waiting, what failed and why, and a history of
-  what happened.
+  what happened. A change Drive refuses (storage full, access taken away) shows at once, on the
+  file too, and can be exported or discarded.
 - **Tray icon** with status, pause and quick actions, and a **search launcher** (`pdfs-prompt`)
  that searches Proton Drive and your home folder together, as its own window, through fuzzel,
  rofi or wofi, or live in `fzf`.
@@ -144,7 +149,7 @@ keys before it leaves the machine, through a Rust implementation of Proton's Dri

 Files you open are decrypted into a local cache so programs can read them. What that means for
 the security of the machine is spelled out in the
-[threat model](docs/ARCHITECTURE.md#8-threat-model-what-this-client-writes-to-disk-in-plaintext).
+[threat model](docs/ARCHITECTURE.md#10-threat-model-what-this-client-writes-to-disk-in-plaintext).

 ## Contributing

@@ -152,6 +157,13 @@ Bug reports, translations and patches are welcome. See [CONTRIBUTING.md](CONTRIB
 workflow and the checks CI runs, and [SECURITY.md](SECURITY.md) to report a vulnerability
 privately.

+## Support
+
+Proton Drive Linux is free and built in spare time. If it saves you a few headaches, you can
+[buy me a coffee](https://buymeacoffee.com/narl).
+
+<a href="https://buymeacoffee.com/narl"><img src="https://img.shields.io/badge/Buy%20me%20a%20coffee-FFDD00?logo=buymeacoffee&logoColor=black" alt="Buy me a coffee"></a>
+
 ## License

 Released under the [MIT License](LICENSE).
@@ -31,7 +31,7 @@ the interesting boundaries are:
  or the wrong key material to Proton.

 What the client deliberately keeps in plaintext on disk, and why, is documented in the
-[threat model](docs/ARCHITECTURE.md#8-threat-model-what-this-client-writes-to-disk-in-plaintext).
+[threat model](docs/ARCHITECTURE.md#10-threat-model-what-this-client-writes-to-disk-in-plaintext).
 Behaviour described there is known and not a vulnerability by itself; a way to make it worse
 than described is.

@@ -23,3 +23,4 @@ tracing-subscriber.workspace = true
 clap.workspace = true
 rpassword.workspace = true
 serde_json.workspace = true
+zeroize.workspace = true
@@ -14,12 +14,45 @@ use pdfs_core::cache::ContentCache;
 use pdfs_core::config::AppDirs;
 use pdfs_core::control::{
    ConflictKeep, ErrorKind, MountKind, RefreshScope, Request as CtlRequest,
-    Response as CtlResponse, RestoreItem as CtlRestoreItem, ShareEntryKind, SyncPhase,
+    Response as CtlResponse, RestoreItem as CtlRestoreItem, ShareEntryKind, SyncIssue, SyncPhase,
    pending_summary,
 };
 use pdfs_core::db::Db;
 use pdfs_core::service;

+/// `println!` for this binary, shadowing std's, which panics when stdout is
+/// closed: `pdfs ls | head` ended in a "Broken pipe" panic once `head` had its
+/// lines. This one hands the failure to [`stdout_written`] instead.
+///
+/// Restoring the default `SIGPIPE` would also stop the panic, but the same
+/// binary runs the daemon, which must not die when a socket's peer goes away.
+macro_rules! println {
+    ($($arg:tt)*) => {{
+        use std::io::Write as _;
+        $crate::stdout_written(writeln!(std::io::stdout(), $($arg)*))
+    }};
+}
+
+/// [`println!`] without the newline.
+macro_rules! print {
+    ($($arg:tt)*) => {{
+        use std::io::Write as _;
+        $crate::stdout_written(write!(std::io::stdout(), $($arg)*))
+    }};
+}
+
+/// Exit on a failed write to stdout. A closed pipe means the reader has all it
+/// wanted, so that exit is a success.
+fn stdout_written(result: std::io::Result<()>) {
+    if let Err(error) = result {
+        if error.kind() == std::io::ErrorKind::BrokenPipe {
+            std::process::exit(0);
+        }
+        eprintln!("Error: writing to stdout: {error}");
+        std::process::exit(1);
+    }
+}
+
 #[derive(Parser)]
 #[command(
    name = "pdfs",
@@ -30,7 +63,7 @@ struct Cli {
    /// Emit machine-readable JSON instead of formatted text.
    ///
    /// Applies to the query commands (`status`, `ls`, `pins`, `sync list`,
-    /// `devices list`, `locations`, `transfers`, `activity`, `cache inspect`). Commands that
+    /// `devices list`, `locations`, `transfers`, `activity`, `trash`, `cache inspect`). Commands that
    /// perform an action keep their human output — a script that needs to know
    /// whether one succeeded has the exit code.
    #[arg(long, global = true)]
@@ -102,6 +135,24 @@ enum Command {
        /// Account email; prompted if omitted.
        #[arg(short, long)]
        username: Option<String>,
+        /// For a two-password account, keep the mailbox password's unlock in the
+        /// system keyring so the daemon starts without asking after every login.
+        /// Without it the unlock lives in kernel memory for this session only.
+        #[arg(long)]
+        remember: bool,
+    },
+    /// Enter the mailbox password of a two-password account so the daemon can
+    /// unlock your files. Needed once per login session.
+    Unlock {
+        /// Keep the unlock in the system keyring instead of kernel memory only.
+        #[arg(long)]
+        remember: bool,
+    },
+    /// Forget the unlock held in kernel memory; the account is locked again.
+    Lock {
+        /// Also remove an unlock kept in the keyring with `--remember`.
+        #[arg(long)]
+        forget: bool,
    },
    /// Forget the stored session.
    Logout,
@@ -285,26 +336,34 @@ enum Command {
    },
    /// Rename a file or folder via the running daemon.
    Rename {
-        /// File/folder path, inside the mountpoint or relative to it.
+        /// File/folder path, inside My files or an on-demand synced folder, or
+        /// relative to the mountpoint.
        path: PathBuf,
        /// New name (a single path component).
        new_name: String,
    },
-    /// Move a file or folder into another folder via the running daemon.
+    /// Move files or folders into another folder via the running daemon.
+    ///
+    /// The paths may be in different locations: My files and any synced
+    /// folder, on-demand or mirrored. The move happens on Proton Drive, so
+    /// nothing is downloaded or uploaded again, unlike `mv` between two
+    /// locations. The last path is the destination folder.
    Move {
-        /// File/folder path, inside the mountpoint or relative to it.
-        path: PathBuf,
-        /// Destination folder path, inside the mountpoint or relative to it.
-        new_parent: PathBuf,
+        /// Files/folders to move, then the destination folder: each inside a
+        /// location, or relative to the mountpoint.
+        #[arg(required = true, num_args = 2.., value_name = "PATH")]
+        paths: Vec<PathBuf>,
    },
    /// Trash a file or folder via the running daemon.
    Rm {
-        /// File/folder path, inside the mountpoint or relative to it.
+        /// File/folder path, inside My files or an on-demand synced folder, or
+        /// relative to the mountpoint.
        path: PathBuf,
    },
    /// Create a folder via the running daemon.
    Mkdir {
-        /// Parent folder path, inside the mountpoint or relative to it.
+        /// Parent folder path, inside My files or an on-demand synced folder,
+        /// or relative to the mountpoint.
        parent: PathBuf,
        /// New folder name (a single path component).
        name: String,
@@ -636,6 +695,25 @@ enum SyncCmd {
    },
    /// List uploads and changes not yet on Proton Drive.
    Queue,
+    /// List queued changes Proton Drive refused or that keep failing, and what to do.
+    Issues,
+    /// Save the content of a queued upload (by id from `sync queue`) to a file.
+    Export {
+        /// Queue id.
+        id: i64,
+        /// Where to save it: a new file, or an existing folder to save it in.
+        dest: PathBuf,
+    },
+    /// Drop a queued change (by id from `sync queue`) and undo it here: a new file
+    /// or folder goes, anything else goes back to what Proton Drive has. Its
+    /// content is lost unless saved with `sync export` first.
+    Discard {
+        /// Queue id.
+        id: i64,
+        /// Do not ask first.
+        #[arg(long)]
+        yes: bool,
+    },
    /// Retry a queued operation now (by id from `sync queue`), or every failed one.
    Retry {
        /// Queue id; omit to retry every failed operation.
@@ -743,7 +821,9 @@ fn main() -> Result<()> {
    let cli = Cli::parse();
    JSON_OUTPUT.store(cli.json, std::sync::atomic::Ordering::Relaxed);
    match cli.command {
-        Command::Login { username } => cmd_login(username),
+        Command::Login { username, remember } => cmd_login(username, remember),
+        Command::Unlock { remember } => cmd_unlock(remember),
+        Command::Lock { forget } => cmd_lock(forget),
        Command::Logout => cmd_logout(),
        Command::Status => cmd_status(),
        Command::Locations => cmd_locations(),
@@ -800,7 +880,10 @@ fn main() -> Result<()> {
            scope,
        } => cmd_search(query, limit, scope),
        Command::Rename { path, new_name } => cmd_rename(path, new_name),
-        Command::Move { path, new_parent } => cmd_move(path, new_parent),
+        Command::Move { mut paths } => {
+            let new_parent = paths.pop().expect("clap requires at least two paths");
+            cmd_move(paths, new_parent)
+        }
        Command::Rm { path } => cmd_rm(path),
        Command::Mkdir { parent, name } => cmd_mkdir(parent, name),
        Command::Upload { sources, parent } => cmd_upload(sources, parent),
@@ -984,7 +1067,17 @@ fn cmd_sync(action: SyncCmd) -> Result<()> {
            })?)?
        }
        SyncCmd::Queue => return cmd_sync_queue(),
+        SyncCmd::Issues => return cmd_sync_issues(),
+        SyncCmd::Export { id, dest } => return cmd_sync_export(id, &dest),
        SyncCmd::Limit { up, down } => return cmd_sync_limit(up, down),
+        SyncCmd::Discard { id, yes } => {
+            if !yes {
+                confirm(&format!(
+                    "Discard queued change {id} and undo it here? Content not exported is lost."
+                ))?;
+            }
+            ok_or_bail(control_request(CtlRequest::DiscardPendingOp { id })?)?
+        }
        SyncCmd::Retry { id } => ok_or_bail(control_request(CtlRequest::RetryPendingOp { id })?)?,
        SyncCmd::Resume { folder: None } => {
            ok_or_bail(control_request(CtlRequest::SetSyncPaused {
@@ -1062,6 +1155,9 @@ fn cmd_sync_queue() -> Result<()> {
                    (false, _) => "due now".to_string(),
                };
                println!("[{}]  {}  {}  ({state})", op.id, op.kind, op.path);
+                if let Some(issue) = op.issue {
+                    println!("      needs attention: {}", issue_text(issue));
+                }
                if let Some(error) = &op.last_error {
                    println!("      failed {} time(s): {error}", op.attempts);
                }
@@ -1073,6 +1169,91 @@ fn cmd_sync_queue() -> Result<()> {
    Ok(())
 }

+/// `pdfs sync issues`: the queued changes that need the user, and what to do.
+fn cmd_sync_issues() -> Result<()> {
+    let response = control_request(CtlRequest::ListPendingOps)?;
+    let items = match response {
+        CtlResponse::PendingOps { items } => items,
+        CtlResponse::Error { message, kind } => bail!("{}", cli_error(kind, &message)),
+        other => bail!("unexpected response: {other:?}"),
+    };
+    let issues: Vec<_> = items.into_iter().filter(|op| op.failing).collect();
+    if json_enabled() {
+        println!("{}", serde_json::to_string_pretty(&issues)?);
+        return Ok(());
+    }
+    if issues.is_empty() {
+        println!("No sync issues.");
+        return Ok(());
+    }
+    for op in issues {
+        println!("[{}]  {}  {}", op.id, op.kind, op.path);
+        match op.issue {
+            Some(issue) => println!("      {}", issue_text(issue)),
+            None => println!("      keeps failing; it is retried."),
+        }
+        if let Some(error) = &op.last_error {
+            println!("      last error: {error}");
+        }
+        if op.exportable {
+            println!(
+                "      save a copy: pdfs sync export {} <file or folder>",
+                op.id
+            );
+        }
+    }
+    Ok(())
+}
+
+/// What a sync issue means, and what the user can do about it.
+fn issue_text(issue: SyncIssue) -> &'static str {
+    match issue {
+        SyncIssue::Quota => {
+            "Proton Drive storage is full. Free up space or upgrade; the change is retried."
+        }
+        SyncIssue::Access => {
+            "you can no longer change this on Proton Drive, for example because a share was \
+             revoked. Save a copy to keep the content."
+        }
+        SyncIssue::Missing => {
+            "the file or its folder is gone from Proton Drive. Save a copy to keep the content."
+        }
+        SyncIssue::Limit => {
+            "the folder holds too many items or is nested too deep. Move the file to another \
+             folder."
+        }
+        SyncIssue::Rejected => {
+            "Proton Drive rejected the change, for example the name. Rename the file."
+        }
+        SyncIssue::Unknown => "Proton Drive refused the change.",
+    }
+}
+
+/// `pdfs sync export`: save a queued upload's content. A folder as `dest`
+/// gets the file under its own name.
+fn cmd_sync_export(id: i64, dest: &Path) -> Result<()> {
+    let mut dest =
+        std::path::absolute(dest).with_context(|| format!("resolving {}", dest.display()))?;
+    if dest.is_dir() {
+        let items = match control_request(CtlRequest::ListPendingOps)? {
+            CtlResponse::PendingOps { items } => items,
+            CtlResponse::Error { message, kind } => bail!("{}", cli_error(kind, &message)),
+            other => bail!("unexpected response: {other:?}"),
+        };
+        let Some(op) = items.iter().find(|op| op.id == id) else {
+            bail!("no queued change {id}; see `pdfs sync queue`");
+        };
+        let name = Path::new(&op.path)
+            .file_name()
+            .with_context(|| format!("{} has no file name", op.path))?;
+        dest.push(name);
+    }
+    ok_or_bail(control_request(CtlRequest::ExportPendingOp {
+        id,
+        dest: dest.display().to_string(),
+    })?)
+}
+
 /// `pdfs sync restore`: list what this machine's device holds, confirm where
 /// each folder should land, then hand the mapping to the daemon.
 ///
@@ -1620,7 +1801,7 @@ fn prompt_line(label: &str) -> Result<String> {
    Ok(line.trim().to_owned())
 }

-fn cmd_login(username: Option<String>) -> Result<()> {
+fn cmd_login(username: Option<String>, remember: bool) -> Result<()> {
    let username = match username {
        Some(u) => u,
        None => prompt_line("Proton email")?,
@@ -1632,11 +1813,14 @@ fn cmd_login(username: Option<String>) -> Result<()> {
        prompt_line("2FA code").map_err(|e| pdfs_core::Error::Other(format!("read 2FA code: {e}")))
    };

+    // Only a two-password account is ever asked for this.
+    let get_mailbox = |attempt: u32| prompt_mailbox(attempt, remember);
+
    let rt = tokio::runtime::Runtime::new()?;
    // Solving a CAPTCHA needs a browser engine, which the CLI has no business
    // carrying. Point at the app that does rather than failing with the raw API
    // message, which reads as "your login is broken".
-    rt.block_on(auth::login(&username, &password, get_totp))
+    rt.block_on(auth::login(&username, &password, get_totp, get_mailbox))
        .map_err(|e| match e {
            pdfs_core::Error::HumanVerificationRequired(_) => anyhow::anyhow!(
                "Proton is asking for a CAPTCHA before it will accept this sign-in.\n\
@@ -1657,9 +1841,88 @@ fn cmd_login(username: Option<String>) -> Result<()> {
    }

    println!("Logged in as {username}. Session stored in the system keyring.");
+    report_key_state();
    Ok(())
 }

+/// Ask for the mailbox password of a two-password account, without echo.
+fn prompt_mailbox(attempt: u32, remember: bool) -> pdfs_core::Result<auth::Mailbox> {
+    if attempt == 0 {
+        eprintln!("This account has a separate mailbox password.");
+    } else {
+        eprintln!("That mailbox password did not unlock the account. Try again.");
+    }
+    let password = rpassword::prompt_password("Mailbox password: ")
+        .map_err(|e| pdfs_core::Error::Other(format!("read mailbox password: {e}")))?;
+    Ok(auth::Mailbox {
+        password: zeroize::Zeroizing::new(password),
+        remember,
+    })
+}
+
+/// Say where the account's keys are held, and what that means for the next login.
+fn report_key_state() {
+    match auth::key_state() {
+        Ok(auth::KeyState::Session) => println!(
+            "Unlocked for this login session only. After you log out or reboot, run `pdfs unlock`."
+        ),
+        Ok(auth::KeyState::Locked) => println!("The account is locked. Run `pdfs unlock`."),
+        _ => {}
+    }
+}
+
+fn cmd_unlock(remember: bool) -> Result<()> {
+    auth::load().context("not logged in (run `pdfs login` first)")?;
+    let rt = tokio::runtime::Runtime::new()?;
+    // Bounded like the login prompt: three wrong answers end the command.
+    let mut attempt = 0;
+    loop {
+        let mailbox = prompt_mailbox(attempt, remember)?;
+        match rt.block_on(auth::unlock(&mailbox.password, remember)) {
+            Ok(()) => break,
+            Err(pdfs_core::Error::WrongMailboxPassword) if attempt < 2 => attempt += 1,
+            Err(e) => return Err(anyhow::Error::new(e).context("unlock failed")),
+        }
+    }
+    // A daemon parked on the locked account would otherwise notice on its next
+    // poll; restarting it makes the mount appear now, as after `pdfs login`.
+    if service::is_active() {
+        service::restart();
+    }
+    println!("Unlocked.");
+    report_key_state();
+    Ok(())
+}
+
+fn cmd_lock(forget: bool) -> Result<()> {
+    auth::lock(forget)?;
+    println!(
+        "Locked. {}",
+        if forget {
+            "Unlock removed from memory and keyring."
+        } else {
+            "Run `pdfs unlock` to unlock again."
+        }
+    );
+    // The running daemon keeps its keys until it restarts; say so, since
+    // "locked" would otherwise suggest the mount stopped.
+    if service::is_active() {
+        println!(
+            "The running daemon keeps its keys until it restarts: `systemctl --user restart proton-drive`."
+        );
+    }
+    Ok(())
+}
+
+/// `stored`, `session` or `locked`: where the account's keys are held.
+fn key_state_name() -> &'static str {
+    match auth::key_state() {
+        Ok(auth::KeyState::Stored) => "stored",
+        Ok(auth::KeyState::Session) => "session",
+        _ => "locked",
+    }
+}
+
 fn cmd_logout() -> Result<()> {
    auth::logout()?;
    println!("Stored session cleared.");
@@ -1687,6 +1950,7 @@ fn cmd_status() -> Result<()> {
            "username": session.as_ref().map(|s| s.username.clone()),
            "user_id": session.as_ref().map(|s| s.user_id.clone()),
            "scopes": session.as_ref().map(|s| s.scopes.clone()),
+            "keys": session.as_ref().map(|_| key_state_name()),
            "mount": mount,
        });
        println!("{}", serde_json::to_string_pretty(&out)?);
@@ -1697,6 +1961,11 @@ fn cmd_status() -> Result<()> {
        Ok(s) => {
            println!("Logged in as {} (user {})", s.username, s.user_id);
            println!("Scopes: {}", s.scopes.join(", "));
+            match key_state_name() {
+                "locked" => println!("Keys: locked — run `pdfs unlock`"),
+                "session" => println!("Keys: unlocked for this login session"),
+                _ => {}
+            }
        }
        Err(pdfs_core::Error::NotLoggedIn) => {
            println!("Not logged in. Run `pdfs login`.");
@@ -1828,7 +2097,7 @@ fn login_poll_delay(attempts: u32) -> std::time::Duration {
    std::time::Duration::from_secs(BASE_SECS.saturating_mul(factor).min(MAX_SECS))
 }

-/// Block until a session is stored, backing off between checks.
+/// Block until a session is stored and unlocked, backing off between checks.
 ///
 /// `load` and `sleep` are parameters rather than direct calls so the backoff
 /// schedule can be tested without a keyring and without real time passing.
@@ -1853,6 +2122,16 @@ where
                sleep(delay);
                attempts = attempts.saturating_add(1);
            }
+            Err(pdfs_core::Error::Locked) => {
+                let delay = login_poll_delay(attempts);
+                if attempts == 0 {
+                    tracing::info!("account is locked; waiting for `pdfs unlock`…");
+                } else {
+                    tracing::debug!(delay_secs = delay.as_secs(), "account still locked");
+                }
+                sleep(delay);
+                attempts = attempts.saturating_add(1);
+            }
            Err(e) => return Err(e.into()),
        }
    }
@@ -1863,10 +2142,13 @@ where
 /// an external unmount triggers a remount; errors back off and retry. This is
 /// the entry point for the systemd user service.
 fn cmd_daemon(mountpoint: Option<PathBuf>) -> Result<()> {
+    // The daemon holds the account's key passphrases in memory; keep them out
+    // of core dumps and away from same-user ptrace.
+    pdfs_core::kernelkey::forbid_dumps();
    loop {
        // Wait until a session is stored. The GUI enables this service on login,
        // but the service may also start at boot before the user has logged in.
-        wait_for_session(|| auth::load().map(|_| ()), std::thread::sleep)?;
+        wait_for_session(auth::ready, pdfs_fuse::idle_sleep)?;

        match mount_once(mountpoint.clone()) {
            Ok(pdfs_fuse::MountOutcome::Shutdown) => {
@@ -1875,13 +2157,13 @@ fn cmd_daemon(mountpoint: Option<PathBuf>) -> Result<()> {
            }
            Ok(pdfs_fuse::MountOutcome::Unmounted) => {
                tracing::warn!("mount ended externally; remounting in 2s");
-                std::thread::sleep(std::time::Duration::from_secs(2));
+                pdfs_fuse::idle_sleep(std::time::Duration::from_secs(2));
            }
            Err(e) => {
                // `{:#}` so the whole anyhow chain lands in the log — the top
                // context alone ("mount failed") never says *why*.
                tracing::error!(error = format!("{e:#}"), "mount failed; retrying in 5s");
-                std::thread::sleep(std::time::Duration::from_secs(5));
+                pdfs_fuse::idle_sleep(std::time::Duration::from_secs(5));
            }
        }
    }
@@ -1939,6 +2221,7 @@ fn mount_once(mountpoint: Option<PathBuf>) -> Result<pdfs_fuse::MountOutcome> {
            sweep_mode: config.resolved_conflict_sweep(),
            upload_limit: config.upload_limit.unwrap_or(0),
            download_limit: config.download_limit.unwrap_or(0),
+            local_first: config.local_first.unwrap_or(true),
        },
    );

@@ -1946,6 +2229,9 @@ fn mount_once(mountpoint: Option<PathBuf>) -> Result<pdfs_fuse::MountOutcome> {
    if let Err(e) = rt.block_on(auth::persist(&session)) {
        tracing::debug!(error = %e, "no new tokens to persist on shutdown");
    }
+    // Dropping the runtime waits for every blocking task, however long; a call
+    // still stuck on Drive would hold the stop until systemd kills it (B165).
+    rt.shutdown_timeout(std::time::Duration::from_secs(2));

    let outcome = result.context("mount failed")?;
    Ok(outcome)
@@ -2439,14 +2725,33 @@ fn cmd_rename(path: PathBuf, new_name: String) -> Result<()> {
    Ok(())
 }

-fn cmd_move(path: PathBuf, new_parent: PathBuf) -> Result<()> {
-    match control_request(CtlRequest::Move {
-        path: path_arg(&path)?,
-        new_parent: path_arg(&new_parent)?,
-    })? {
-        CtlResponse::Ok { message } => println!("{message}"),
-        CtlResponse::Error { message, kind } => bail!("{}", cli_error(kind, &message)),
-        other => bail!("unexpected response: {other:?}"),
+/// Move each of `sources` into `new_parent`, one request each. A refusal names
+/// its source and the rest still move; the command fails if any did not.
+fn cmd_move(sources: Vec<PathBuf>, new_parent: PathBuf) -> Result<()> {
+    let new_parent = path_arg(&new_parent)?;
+    let mut failed = 0;
+    for source in &sources {
+        let outcome = path_arg(source).and_then(|path| {
+            match control_request(CtlRequest::Move {
+                path,
+                new_parent: new_parent.clone(),
+            })? {
+                CtlResponse::Ok { message } => Ok(message),
+                CtlResponse::Error { message, kind } => bail!("{}", cli_error(kind, &message)),
+                other => bail!("unexpected response: {other:?}"),
+            }
+        });
+        match outcome {
+            Ok(message) => println!("{message}"),
+            Err(e) if sources.len() == 1 => return Err(e),
+            Err(e) => {
+                eprintln!("{}: {e:#}", source.display());
+                failed += 1;
+            }
+        }
+    }
+    if failed > 0 {
+        bail!("{failed} of {} could not be moved", sources.len());
    }
    Ok(())
 }
@@ -2524,7 +2829,11 @@ fn cmd_diagnostics() -> Result<()> {
 }

 fn cmd_trash() -> Result<()> {
-    match control_request(CtlRequest::ListTrash)? {
+    let response = control_request(CtlRequest::ListTrash)?;
+    if emit_json(&response)? {
+        return Ok(());
+    }
+    match response {
        CtlResponse::Entries { entries } if entries.is_empty() => println!("(trash is empty)"),
        CtlResponse::Entries { entries } => {
            for e in entries {
@@ -3036,6 +3345,19 @@ fn cmd_diagnose() -> Result<()> {
    match pdfs_core::auth::load() {
        Ok(session) => {
            report.finding(DiagnoseLevel::Ok, "  keyring session", session.username);
+            match key_state_name() {
+                "locked" => report.finding(
+                    DiagnoseLevel::Fail,
+                    "  account keys",
+                    "locked — run `pdfs unlock` (the daemon waits for it)",
+                ),
+                "session" => report.finding(
+                    DiagnoseLevel::Ok,
+                    "  account keys",
+                    "unlocked for this login session",
+                ),
+                _ => report.finding(DiagnoseLevel::Ok, "  account keys", "stored in the keyring"),
+            }
        }
        Err(e) => {
            // A locked keyring and an absent login look the same from here, so
@@ -3334,6 +3656,21 @@ mod login_wait_tests {
        );
    }

+    #[test]
+    fn a_locked_account_is_waited_on_until_it_is_unlocked() {
+        let mut checks = vec![
+            Ok(()),
+            Err(pdfs_core::Error::Locked),
+            Err(pdfs_core::Error::NotLoggedIn),
+            Err(pdfs_core::Error::Locked),
+        ];
+        let mut slept = 0;
+
+        wait_for_session(|| checks.pop().unwrap(), |_| slept += 1).unwrap();
+
+        assert_eq!(slept, 3, "locked and signed-out are both waited out");
+    }
+
    #[test]
    fn a_stored_session_is_not_waited_for_at_all() {
        let mut slept = 0;
@@ -3366,6 +3703,7 @@ mod login_wait_tests {
            shared_by_unverified: false,
            trashed_at: 0,
            trashed_from: None,
+            issue: None,
        };
        assert_eq!(shared_by_line(&entry), None, "no invitation, no line");
        entry.shared_by = "alice@proton.me".into();
@@ -28,3 +28,5 @@ dbus-secret-service-keyring-store.workspace = true
 parking_lot.workspace = true
 async-trait.workspace = true
 libc.workspace = true
+zeroize.workspace = true
+base64.workspace = true
@@ -1,22 +1,50 @@
 //! Login, session persistence, and Drive-client construction.
 //!
 //! A successful login is persisted to the OS keyring as a single JSON blob
-//! holding the resumable session tokens plus the mailbox password (needed to
-//! rebuild the key chain on resume). The daemon resumes from this blob with no
-//! interactive step; the refresh token auto-renews via the HTTP client's 401
-//! path, so no fresh 2FA is required until the refresh token itself expires.
+//! holding the resumable session tokens, the account's key salts and — unless
+//! the user chose otherwise — the per-key *passphrases* derived from the
+//! mailbox password. The password itself is never stored: the passphrases are
+//! what it exists to produce, and they are enough to rebuild the key chain on
+//! resume. The daemon resumes from this blob with no interactive step; the
+//! refresh token auto-renews via the HTTP client's 401 path, so no fresh 2FA is
+//! required until the refresh token itself expires.
+//!
+//! # Two-password accounts
+//!
+//! An account with a separate mailbox password exists precisely so that no one
+//! login holds the means to read the data. Storing that password in the keyring
+//! would defeat it, so such an account is **locked by default**: its
+//! passphrases are kept only in the kernel keyring ([`crate::kernelkey`]), for
+//! the length of the user's session, and `pdfs unlock` (or the app) supplies
+//! them again after each login. Storing them in the Secret Service as well is
+//! an explicit opt-in ([`Mailbox::remember`]). Single-password accounts have no
+//! such separation to protect and are stored, as they always were.

+use std::collections::BTreeMap;
+
+use base64::Engine as _;
+use base64::engine::general_purpose::STANDARD as BASE64;
 use keyring_core::Entry;
 use proton_drive_rs::{KeySalt, ProtonDriveClient};
+use proton_sdk::account::KeyPassphrases;
 use proton_sdk::api::{HumanVerification, HumanVerificationCredential};
 use proton_sdk::cache::EncryptedCacheRepository;
 use proton_sdk::config::ProtonClientConfiguration;
+use proton_sdk::error::ProtonError;
 use proton_sdk::session::{PasswordMode, ProtonApiSession, ResumeParameters};
 use proton_sdk::telemetry::TracingTelemetry;
 use serde::{Deserialize, Serialize};
+use zeroize::Zeroizing;

 use crate::config::{APP_VERSION, AppDirs, KEYRING_SERVICE, USER_AGENT};
 use crate::error::{Error, Result};
+use crate::kernelkey;
+
+/// How often a wrong mailbox password is asked for again before the login gives up.
+const MAILBOX_ATTEMPTS: u32 = 3;
+
+/// Domain-separation label for the key that encrypts the persistent entity cache.
+const ENTITY_CACHE_PURPOSE: &[u8] = b"pdfs entity cache v1";

 /// Fixed keyring account name for the single stored session blob.
 const KEYRING_USER: &str = "session";
@@ -32,8 +60,11 @@ pub struct StoredSession {
    pub scopes: Vec<String>,
    /// `1` = single password, `2` = dual (Proton wire value).
    pub password_mode: u8,
-    /// Mailbox (data) password — required by `ProtonDriveClient::new` to derive
-    /// the key chain. Lives only in the OS keyring, never on disk in cleartext.
+    /// The mailbox password of a blob written by 3.0.x and earlier.
+    ///
+    /// Read only, to migrate: [`resume_client`] derives the passphrases from it
+    /// once and writes the blob back without it. Never serialized again.
+    #[serde(default, skip_serializing)]
    pub mailbox_password: String,
    /// The account's key salts, captured at login.
    ///
@@ -49,6 +80,11 @@ pub struct StoredSession {
    /// backfilling) them.
    #[serde(default)]
    pub key_salts: Vec<KeySalt>,
+    /// Per-key passphrases (key id → base64), when the user keeps them in the
+    /// keyring: always for a single-password account, by opt-in for a
+    /// two-password one. `None` means they are not stored here.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub key_passphrases: Option<BTreeMap<String, String>>,
 }

 impl StoredSession {
@@ -89,6 +125,26 @@ fn keyring_entry() -> Result<Entry> {
    Ok(Entry::new(KEYRING_SERVICE, KEYRING_USER)?)
 }

+/// What the user answered when asked for the mailbox password.
+pub struct Mailbox {
+    pub password: Zeroizing<String>,
+    /// Keep the derived passphrases in the keyring, so the daemon unlocks by
+    /// itself after every login. Off by default: it trades the protection a
+    /// separate mailbox password gives for convenience.
+    pub remember: bool,
+}
+
+/// Where the passphrases that unlock this account's keys currently live.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum KeyState {
+    /// In the keyring, available after every login.
+    Stored,
+    /// In kernel memory for this login session only.
+    Session,
+    /// Nowhere: the mailbox password has to be entered (`pdfs unlock`).
+    Locked,
+}
+
 /// Run an interactive SRP + (optional) 2FA login and persist the session.
 ///
 /// `get_totp` is only invoked when the account requires a second factor, so
@@ -96,14 +152,19 @@ fn keyring_entry() -> Result<Entry> {
 /// more than once — [`login_interactive`] re-runs the whole login after human
 /// verification, and a 2FA account needs a fresh code on that second attempt.
 ///
+/// `get_mailbox` is only invoked for a two-password account. It receives the
+/// number of earlier wrong answers (so a prompt can say "try again") and is
+/// asked at most [`MAILBOX_ATTEMPTS`] times; an `Err` from it aborts the login.
+///
 /// A gated login fails with [`Error::HumanVerificationRequired`]; a front-end
 /// that can present the challenge should use [`login_interactive`] instead.
 pub async fn login(
    username: &str,
    password: &str,
    get_totp: impl Fn() -> Result<String>,
+    get_mailbox: impl Fn(u32) -> Result<Mailbox>,
 ) -> Result<()> {
-    login_verified(username, password, None, get_totp).await
+    login_verified(username, password, None, get_totp, get_mailbox).await
 }

 /// [`login`], able to answer a human-verification gate rather than fail on it.
@@ -123,12 +184,20 @@ pub async fn login_interactive(
    username: &str,
    password: &str,
    get_totp: impl Fn() -> Result<String>,
+    get_mailbox: impl Fn(u32) -> Result<Mailbox>,
    get_hv: impl FnOnce(HumanVerification) -> Result<HumanVerificationCredential>,
 ) -> Result<()> {
-    match login_verified(username, password, None, &get_totp).await {
+    match login_verified(username, password, None, &get_totp, &get_mailbox).await {
        Err(Error::HumanVerificationRequired(hv)) => {
            let credential = get_hv(*hv)?;
-            login_verified(username, password, Some(&credential), &get_totp).await
+            login_verified(
+                username,
+                password,
+                Some(&credential),
+                &get_totp,
+                &get_mailbox,
+            )
+            .await
        }
        other => other,
    }
@@ -145,15 +214,18 @@ pub async fn login_verified(
    password: &str,
    verification: Option<&HumanVerificationCredential>,
    get_totp: impl Fn() -> Result<String>,
+    get_mailbox: impl Fn(u32) -> Result<Mailbox>,
 ) -> Result<()> {
-    let mut session = ProtonApiSession::begin_verified(
+    let password = Zeroizing::new(password.to_owned());
+    let session = ProtonApiSession::begin_verified(
        client_config(),
        username,
        password.as_bytes(),
        verification,
    )
    .await
-    .map_err(classify_verification_gate)?;
+    .map_err(classify_verification_gate);
+    let mut session = session?;

    if session.is_waiting_for_second_factor() {
        let code = get_totp()?;
@@ -163,38 +235,38 @@ pub async fn login_verified(
    // Grab the key salts while this access token still has the `locked` scope:
    // after its first refresh it never will again, and without them no later
    // resume can unlock the key chain. See `StoredSession::key_salts`.
-    let client = ProtonDriveClient::new(&session, password.as_bytes().to_vec());
-    let key_salts = client.account().key_salts().await?;
+    let key_salts = ProtonDriveClient::new(&session, Vec::new())
+        .account()
+        .key_salts()
+        .await?;

-    register_refresh_handler(&session, password.to_owned(), key_salts.clone());
-
-    save(&session, password, key_salts).await?;
-    Ok(())
-}
-
-/// Lift a human-verification gate out of the generic API error into the typed
-/// variant a front-end can act on.
-///
-/// Only a gate that names a solvable method is converted. A `9001` with no
-/// `Details`, or one offering only `email`/`sms`, stays a plain API error:
-/// promoting it would send the UI to open a verification page it cannot
-/// complete, which reads to the user as a hang rather than a refusal.
-fn classify_verification_gate(e: proton_sdk::error::ProtonError) -> Error {
-    let proton_sdk::error::ProtonError::Api(api) = &e else {
-        return e.into();
+    // A single-password account's mailbox password is the login password. A
+    // two-password one has a second secret the user must type, and it is checked
+    // against the account now — a typo found at login is a retry, found later it
+    // is a daemon that never mounts.
+    let (passphrases, remember) = match session.password_mode() {
+        PasswordMode::Single => (
+            derive_verified(&session, password.as_bytes(), key_salts.clone()).await?,
+            true,
+        ),
+        PasswordMode::Dual => {
+            let mut attempt = 0;
+            loop {
+                let mailbox = get_mailbox(attempt)?;
+                match derive_verified(&session, mailbox.password.as_bytes(), key_salts.clone())
+                    .await
+                {
+                    Ok(passphrases) => break (passphrases, mailbox.remember),
+                    Err(Error::WrongMailboxPassword) if attempt + 1 < MAILBOX_ATTEMPTS => {
+                        attempt += 1;
+                    }
+                    Err(e) => return Err(e),
+                }
+            }
+        }
    };
-    match api.human_verification() {
-        Some(hv) if hv.supports_captcha() => Error::HumanVerificationRequired(Box::new(hv)),
-        _ => e.into(),
-    }
-}

-/// Persist the session's current tokens, mailbox password and key salts.
-pub async fn save(
-    session: &ProtonApiSession,
-    mailbox_password: &str,
-    key_salts: Vec<KeySalt>,
-) -> Result<()> {
+    register_refresh_handler(&session);
    let tokens = session.current_tokens().await;
    let stored = StoredSession {
        session_id: session.session_id().as_str().to_owned(),
@@ -207,10 +279,103 @@ pub async fn save(
            PasswordMode::Single => 1,
            PasswordMode::Dual => 2,
        },
-        mailbox_password: mailbox_password.to_owned(),
+        mailbox_password: String::new(),
        key_salts,
+        key_passphrases: None,
    };
-    let json = serde_json::to_string(&stored)?;
+    keep_passphrases(stored, &passphrases, remember)
+}
+
+/// Derive the key passphrases from `mailbox` and prove they unlock the account.
+///
+/// [`Error::WrongMailboxPassword`] means the account answered and the password
+/// is wrong; any other error says nothing about the password (no network, an
+/// API fault) and must not be reported as a typo.
+async fn derive_verified(
+    session: &ProtonApiSession,
+    mailbox: &[u8],
+    key_salts: Vec<KeySalt>,
+) -> Result<KeyPassphrases> {
+    let client = ProtonDriveClient::with_key_salts(session, mailbox.to_vec(), key_salts);
+    client.account().unlock().await.map_err(|e| match e {
+        ProtonError::KeysLocked => Error::WrongMailboxPassword,
+        other => other.into(),
+    })?;
+    Ok(client.account().key_passphrases().await?)
+}
+
+/// Write `stored` with the passphrases in the place the user chose: the
+/// keyring (`remember`) or kernel memory only. Whichever is not chosen is
+/// cleared, so a revoked choice never leaves a copy behind.
+///
+/// The kernel entry is written first. If it cannot be (no keyring support), the
+/// secret is *not* quietly stored somewhere weaker: the blob is written locked
+/// and the error says so.
+fn keep_passphrases(
+    mut stored: StoredSession,
+    passphrases: &KeyPassphrases,
+    remember: bool,
+) -> Result<()> {
+    let outcome = if remember {
+        stored.key_passphrases = Some(encode(passphrases));
+        // Best-effort: a system without a kernel keyring has nothing to clear.
+        let _ = kernelkey::clear();
+        Ok(())
+    } else {
+        stored.key_passphrases = None;
+        kernelkey::store(&encode_secret(passphrases)).map_err(|e| {
+            Error::Other(format!(
+                "the kernel keyring is unavailable, so the unlock cannot be kept for this session: {e}"
+            ))
+        })
+    };
+    write_stored(&stored)?;
+    outcome
+}
+
+fn encode(passphrases: &KeyPassphrases) -> BTreeMap<String, String> {
+    passphrases
+        .iter()
+        .map(|(id, secret)| (id.to_owned(), BASE64.encode(secret)))
+        .collect()
+}
+
+fn decode(encoded: &BTreeMap<String, String>) -> Option<KeyPassphrases> {
+    let mut passphrases = KeyPassphrases::new();
+    for (id, secret) in encoded {
+        passphrases.insert(id.clone(), BASE64.decode(secret).ok()?);
+    }
+    (!passphrases.is_empty()).then_some(passphrases)
+}
+
+/// The kernel-keyring payload: the same map as the blob's, as JSON.
+fn encode_secret(passphrases: &KeyPassphrases) -> Zeroizing<Vec<u8>> {
+    Zeroizing::new(serde_json::to_vec(&encode(passphrases)).unwrap_or_default())
+}
+
+fn decode_secret(secret: &[u8]) -> Option<KeyPassphrases> {
+    decode(&serde_json::from_slice(secret).ok()?)
+}
+
+/// Lift a human-verification gate out of the generic API error into the typed
+/// variant a front-end can act on.
+///
+/// Only a gate that names a solvable method is converted. A `9001` with no
+/// `Details`, or one offering only `email`/`sms`, stays a plain API error:
+/// promoting it would send the UI to open a verification page it cannot
+/// complete, which reads to the user as a hang rather than a refusal.
+fn classify_verification_gate(e: ProtonError) -> Error {
+    let ProtonError::Api(api) = &e else {
+        return e.into();
+    };
+    match api.human_verification() {
+        Some(hv) if hv.supports_captcha() => Error::HumanVerificationRequired(Box::new(hv)),
+        _ => e.into(),
+    }
+}
+
+fn write_stored(stored: &StoredSession) -> Result<()> {
+    let json = Zeroizing::new(serde_json::to_string(stored)?);
    keyring_entry()?.set_password(&json)?;
    Ok(())
 }
@@ -225,12 +390,93 @@ pub fn load() -> Result<StoredSession> {
    }
 }

+/// Where the passphrases for the stored session live right now.
+///
+/// Reads the kernel keyring and the stored blob only; never the network.
+pub fn key_state() -> Result<KeyState> {
+    Ok(key_state_of(&load()?))
+}
+
+fn key_state_of(stored: &StoredSession) -> KeyState {
+    match find_passphrases(stored) {
+        Ok(Some((_, origin))) => origin,
+        // A 3.0.x blob still holds its password; `resume_client` migrates it.
+        _ if !stored.mailbox_password.is_empty() => KeyState::Stored,
+        _ => KeyState::Locked,
+    }
+}
+
+/// Whether the stored session can be resumed without asking the user:
+/// `Ok` when it can, [`Error::NotLoggedIn`] or [`Error::Locked`] when not.
+/// What the daemon waits on before it mounts.
+pub fn ready() -> Result<()> {
+    match key_state_of(&load()?) {
+        KeyState::Locked => Err(Error::Locked),
+        _ => Ok(()),
+    }
+}
+
+/// The passphrases the stored session can use without being asked, and which
+/// of the two places they came from. Prefers the keyring blob: it is what the
+/// user opted into. A corrupt entry is treated as absent, so it reads as
+/// locked instead of wedging the daemon.
+fn find_passphrases(stored: &StoredSession) -> Result<Option<(KeyPassphrases, KeyState)>> {
+    if let Some(found) = stored.key_passphrases.as_ref().and_then(decode) {
+        return Ok(Some((found, KeyState::Stored)));
+    }
+    match kernelkey::load() {
+        Ok(Some(secret)) => Ok(decode_secret(&secret).map(|p| (p, KeyState::Session))),
+        Ok(None) => Ok(None),
+        // No keyring on this system: nothing was ever kept there.
+        Err(e) => {
+            tracing::debug!(error = %e, "kernel keyring not readable; treating the account as locked");
+            Ok(None)
+        }
+    }
+}
+
+/// Supply the mailbox password of a locked account.
+///
+/// Verifies it against the account, then keeps the derived passphrases in
+/// kernel memory for this login session — or, with `remember`, in the keyring.
+/// A daemon waiting on [`Error::Locked`] picks them up on its next attempt.
+///
+/// Fails with [`Error::WrongMailboxPassword`] for a wrong password, which
+/// changes nothing, and [`Error::ReloginRequired`] for a session that predates
+/// stored key salts.
+pub async fn unlock(mailbox: &str, remember: bool) -> Result<()> {
+    let stored = load()?;
+    if stored.key_salts.is_empty() {
+        return Err(Error::ReloginRequired);
+    }
+    let mailbox = Zeroizing::new(mailbox.to_owned());
+    let session = ProtonApiSession::resume(client_config(), stored.to_params())?;
+    register_refresh_handler(&session);
+    let passphrases =
+        derive_verified(&session, mailbox.as_bytes(), stored.key_salts.clone()).await?;
+    keep_passphrases(stored, &passphrases, remember)
+}
+
+/// Drop the passphrases held in kernel memory, so the account is locked again
+/// until [`unlock`]. With `forget`, also those in the keyring blob.
+pub fn lock(forget: bool) -> Result<()> {
+    kernelkey::clear()?;
+    if forget {
+        let mut stored = load()?;
+        if stored.key_passphrases.take().is_some() {
+            write_stored(&stored)?;
+        }
+    }
+    Ok(())
+}
+
 /// Forget the persisted session (best-effort; absent entry is not an error).
 pub fn logout() -> Result<()> {
    // The persisted entity cache describes the account being logged out of. It
-    // is encrypted under that account's mailbox password, but leaving it behind
-    // would also mean the next account inherits a store it can only ever read as
-    // misses. Best-effort: failing to remove a cache must not block the logout.
+    // is encrypted under a key derived from that account's passphrases, but
+    // leaving it behind would also mean the next account inherits a store it can
+    // only ever read as misses. Best-effort: failing to remove a cache must not
+    // block the logout.
    if let Ok(dirs) = AppDirs::new() {
        let path = dirs.state_dir().join("sdk_cache.db");
        if let Some(cache) = crate::sdkcache::SdkCache::opened()
@@ -242,6 +488,9 @@ pub fn logout() -> Result<()> {
            let _ = std::fs::remove_file(format!("{}{suffix}", path.display()));
        }
    }
+    if let Err(e) = kernelkey::clear() {
+        tracing::warn!(error = %e, "clearing the kernel-keyring unlock on logout failed");
+    }
    match keyring_entry()?.delete_credential() {
        Ok(()) | Err(keyring_core::Error::NoEntry) => Ok(()),
        Err(e) => Err(e.into()),
@@ -250,44 +499,87 @@ pub fn logout() -> Result<()> {

 /// Resume a persisted session and build an authenticated Drive client.
 ///
-/// Returns `Error::NotLoggedIn` when no session has been saved. The caller is
-/// responsible for persisting rotated tokens over the session's lifetime via
-/// [`persist`] — Proton refresh tokens are single-use, so a refresh that is not
-/// written back leaves the keyring holding a stale (now-invalid) refresh token,
-/// and the next resume fails with `InvalidRefreshToken`.
+/// Returns `Error::NotLoggedIn` when no session has been saved and
+/// [`Error::Locked`] when the account is waiting for its mailbox password. Tokens
+/// the session rotates are written back to the keyring as they happen (see
+/// [`register_refresh_handler`]); Proton refresh tokens are single-use, so a
+/// refresh that is not written back would leave the keyring holding a stale
+/// refresh token, and the next resume would fail with `InvalidRefreshToken`.
+///
+/// Makes no network call for an account whose passphrases are already known, so
+/// a daemon starting offline can still mount from its cache.
 pub async fn resume_client() -> Result<(ProtonDriveClient, ProtonApiSession)> {
    let stored = load()?;
    let session = ProtonApiSession::resume(client_config(), stored.to_params())?;
-    let password = stored.mailbox_password.clone();
+    register_refresh_handler(&session);

-    // Blobs written before key salts were persisted have none: fetch them once
-    // more and write them back, which only works while the stored access token
-    // still carries the `locked` scope. If it doesn't, the account must be
-    // logged into again — no refresh can restore that scope.
-    let key_salts = if stored.key_salts.is_empty() {
-        register_refresh_handler(&session, password.clone(), Vec::new());
-        let probe = ProtonDriveClient::new(&session, password.clone().into_bytes());
-        let salts = probe.account().key_salts().await.map_err(|e| match &e {
-            proton_sdk::error::ProtonError::Api(api) if api.is_insufficient_scope() => {
-                Error::ReloginRequired
-            }
-            _ => e.into(),
-        })?;
-        save(&session, &password, salts.clone()).await?;
-        salts
-    } else {
-        stored.key_salts
+    let passphrases = match find_passphrases(&stored)? {
+        Some((passphrases, _)) => passphrases,
+        None if !stored.mailbox_password.is_empty() => migrate_legacy(&session, &stored).await?,
+        None => return Err(Error::Locked),
    };

-    register_refresh_handler(&session, password.clone(), key_salts.clone());
-
    let client = tune(
-        ProtonDriveClient::with_key_salts(&session, password.clone().into_bytes(), key_salts),
-        password.as_bytes(),
+        ProtonDriveClient::with_key_passphrases(&session, passphrases.clone()),
+        &passphrases,
    );
    Ok((client, session))
 }

+/// Turn a blob written by 3.0.x — which holds the mailbox password — into one
+/// that holds passphrases, so the password stops being stored.
+///
+/// The old login saved whatever was typed as the mailbox password, which for a
+/// two-password account is the *login* password and unlocks nothing. That is
+/// checked here: a password the account rejects leaves the account locked (and
+/// the stored copy gone) rather than failing every start forever.
+async fn migrate_legacy(
+    session: &ProtonApiSession,
+    stored: &StoredSession,
+) -> Result<KeyPassphrases> {
+    let legacy = Zeroizing::new(stored.mailbox_password.clone());
+
+    // Blobs from before key salts were persisted have none: fetch them once
+    // more, which only works while the stored access token still carries the
+    // `locked` scope. If it doesn't, the account must be logged into again — no
+    // refresh can restore that scope.
+    let key_salts = if stored.key_salts.is_empty() {
+        ProtonDriveClient::new(session, Vec::new())
+            .account()
+            .key_salts()
+            .await
+            .map_err(|e| match &e {
+                ProtonError::Api(api) if api.is_insufficient_scope() => Error::ReloginRequired,
+                _ => e.into(),
+            })?
+    } else {
+        stored.key_salts.clone()
+    };
+
+    let mut migrated = stored.clone();
+    migrated.mailbox_password = String::new();
+    migrated.key_salts = key_salts.clone();
+
+    match derive_verified(session, legacy.as_bytes(), key_salts).await {
+        Ok(passphrases) => {
+            migrated.key_passphrases = Some(encode(&passphrases));
+            write_stored(&migrated)?;
+            tracing::info!(
+                "migrated the stored session from a mailbox password to key passphrases"
+            );
+            Ok(passphrases)
+        }
+        Err(Error::WrongMailboxPassword) => {
+            write_stored(&migrated)?;
+            tracing::warn!(
+                "the stored password does not unlock the account's keys; unlock required"
+            );
+            Err(Error::Locked)
+        }
+        Err(e) => Err(e),
+    }
+}
+
 /// The client settings every front-end wants, applied wherever a
 /// [`ProtonDriveClient`] is built for real work.
 ///
@@ -301,23 +593,24 @@ pub async fn resume_client() -> Result<(ProtonDriveClient, ProtonApiSession)> {
 ///   failure point per write instead of three.
 /// - **A persistent entity cache** ([`crate::sdkcache`]), so a restart does not
 ///   re-fetch and re-decrypt the tree the previous run already walked. It is
-///   wrapped in the SDK's [`EncryptedCacheRepository`] keyed by the mailbox
-///   password, so the decrypted node names it holds are not readable from the
-///   file alone — and a password change simply reads as a cold cache, since the
-///   SDK treats an undecryptable entry as a miss and clears the store.
+///   wrapped in the SDK's [`EncryptedCacheRepository`] keyed by a secret derived
+///   from the key passphrases, so the decrypted node names it holds are not
+///   readable from the file alone — and a password change simply reads as a cold
+///   cache, since the SDK treats an undecryptable entry as a miss and clears the
+///   store.
 ///
 ///   Opening it is best-effort: a store this process cannot open costs cache
 ///   hits, not the session, so the client falls back to the SDK's in-memory
 ///   default.
-fn tune(client: ProtonDriveClient, mailbox_password: &[u8]) -> ProtonDriveClient {
+fn tune(client: ProtonDriveClient, passphrases: &KeyPassphrases) -> ProtonDriveClient {
    let client = client
        .with_telemetry(TracingTelemetry::shared())
        .with_small_file_upload(true);
    match AppDirs::new().and_then(|dirs| crate::sdkcache::SdkCache::shared(&dirs)) {
-        Ok(cache) => client.with_entity_repository(EncryptedCacheRepository::shared(
-            cache,
-            mailbox_password.to_vec(),
-        )),
+        Ok(cache) => {
+            let key = passphrases.derive_secret(ENTITY_CACHE_PURPOSE);
+            client.with_entity_repository(EncryptedCacheRepository::shared(cache, key.to_vec()))
+        }
        Err(e) => {
            tracing::warn!(error = %e, "persistent SDK entity cache unavailable; using memory");
            client
@@ -327,49 +620,105 @@ fn tune(client: ProtonDriveClient, mailbox_password: &[u8]) -> ProtonDriveClient

 /// Write the session's current tokens back to the keyring.
 ///
-/// The session does not carry the mailbox password (it is only needed to rebuild
-/// the key chain on resume), so it is re-read from the existing stored blob and
-/// preserved. Call whenever the session may have rotated its tokens through the
-/// 401-refresh path so a later [`resume_client`] presents a live refresh token.
+/// Everything else in the stored blob — salts, passphrases — is preserved, so
+/// this never undoes an [`unlock`] or [`lock`] made since the session started.
+/// Call whenever the session may have rotated its tokens so a later
+/// [`resume_client`] presents a live refresh token.
 pub async fn persist(session: &ProtonApiSession) -> Result<()> {
-    let stored = load()?;
-    save(session, &stored.mailbox_password, stored.key_salts).await
+    let tokens = session.current_tokens().await;
+    store_tokens(tokens.access_token, tokens.refresh_token)
 }

-fn register_refresh_handler(
-    session: &ProtonApiSession,
-    mailbox_password: String,
-    key_salts: Vec<KeySalt>,
-) {
-    let session_id = session.session_id().as_str().to_owned();
-    let username = session.username().to_owned();
-    let user_id = session.user_id().as_str().to_owned();
-    let scopes = session.scopes().to_vec();
-    let password_mode = match session.password_mode() {
-        PasswordMode::Single => 1,
-        PasswordMode::Dual => 2,
-    };
+fn store_tokens(access_token: String, refresh_token: String) -> Result<()> {
+    let mut stored = load()?;
+    stored.access_token = access_token;
+    stored.refresh_token = refresh_token;
+    write_stored(&stored)
+}

+/// Persist rotated tokens the moment the session obtains them.
+///
+/// The handler re-reads the stored blob instead of capturing one, so it cannot
+/// write back a stale copy over a later unlock or lock — and cannot resurrect a
+/// session that was logged out while the daemon still ran.
+fn register_refresh_handler(session: &ProtonApiSession) {
    session.http().set_on_tokens_refreshed(move |tokens| {
-        let stored = StoredSession {
-            session_id: session_id.clone(),
-            username: username.clone(),
-            user_id: user_id.clone(),
-            access_token: tokens.access_token,
-            refresh_token: tokens.refresh_token,
-            scopes: scopes.clone(),
-            password_mode,
-            mailbox_password: mailbox_password.clone(),
-            key_salts: key_salts.clone(),
-        };
-        if let Ok(json) = serde_json::to_string(&stored)
-            && let Ok(entry) = keyring_entry()
-        {
-            if let Err(e) = entry.set_password(&json) {
-                tracing::warn!(error = %e, "failed to auto-persist refreshed tokens in keyring");
-            } else {
-                tracing::info!("successfully auto-persisted refreshed tokens in keyring");
+        match store_tokens(tokens.access_token, tokens.refresh_token) {
+            Ok(()) => tracing::info!("successfully auto-persisted refreshed tokens in keyring"),
+            Err(Error::NotLoggedIn) => {}
+            Err(e) => {
+                tracing::warn!(error = %e, "failed to auto-persist refreshed tokens in keyring")
            }
        }
    });
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn passphrases() -> KeyPassphrases {
+        let mut p = KeyPassphrases::new();
+        p.insert("key-a", b"alpha".to_vec());
+        p.insert("key-b", vec![0, 255, 7]);
+        p
+    }
+
+    fn blob(extra: &str) -> String {
+        format!(
+            r#"{{"session_id":"s","username":"u","user_id":"i","access_token":"a",
+            "refresh_token":"r","scopes":[],"password_mode":2{extra}}}"#
+        )
+    }
+
+    #[test]
+    fn passphrases_survive_the_blob_encoding() {
+        let decoded = decode(&encode(&passphrases())).expect("decodes");
+        assert_eq!(decoded, passphrases());
+    }
+
+    #[test]
+    fn passphrases_survive_the_kernel_payload_encoding() {
+        let decoded = decode_secret(&encode_secret(&passphrases())).expect("decodes");
+        assert_eq!(decoded, passphrases());
+    }
+
+    #[test]
+    fn corrupt_or_empty_secrets_read_as_absent() {
+        assert!(decode_secret(b"not json").is_none());
+        assert!(decode(&BTreeMap::new()).is_none());
+        assert!(decode(&BTreeMap::from([("k".into(), "!!!".into())])).is_none());
+    }
+
+    #[test]
+    fn legacy_blob_is_read_but_its_password_is_never_written_back() {
+        let stored: StoredSession =
+            serde_json::from_str(&blob(r#","mailbox_password":"hunter2""#)).unwrap();
+        assert_eq!(stored.mailbox_password, "hunter2");
+        assert!(stored.key_passphrases.is_none());
+
+        let written = serde_json::to_string(&stored).unwrap();
+        assert!(!written.contains("hunter2"));
+        assert!(!written.contains("mailbox_password"));
+    }
+
+    #[test]
+    fn locked_blob_has_no_passphrases_field() {
+        let stored: StoredSession = serde_json::from_str(&blob("")).unwrap();
+        assert!(
+            serde_json::to_string(&stored)
+                .unwrap()
+                .find("key_passphrases")
+                .is_none()
+        );
+    }
+
+    #[test]
+    fn stored_passphrases_win_over_the_kernel_keyring() {
+        let mut stored: StoredSession = serde_json::from_str(&blob("")).unwrap();
+        stored.key_passphrases = Some(encode(&passphrases()));
+        let (found, origin) = find_passphrases(&stored).unwrap().unwrap();
+        assert_eq!(origin, KeyState::Stored);
+        assert_eq!(found, passphrases());
+    }
+}
@@ -91,7 +91,7 @@ const TOUCH_FLUSH_AT: usize = 256;
 ///
 /// Public because it is the *contract* a block has to satisfy, not a detail of
 /// this cache: the network read path validates against it too, so a block that
-/// comes back short is refused before it can truncate a file (bugs.md B84).
+/// comes back short is refused before it can truncate a file (`docs/BUGS.md` B84).
 pub fn block_len(size: u64, idx: u64) -> u64 {
    let start = idx.saturating_mul(BLOCK_SIZE);
    size.saturating_sub(start).min(BLOCK_SIZE)
@@ -311,8 +311,7 @@ struct PinFile {
    pins: BTreeMap<String, Pin>,
 }

-/// What a staged file actually contains, written beside it as `<name>.json`
-/// (offline.md Phase 2).
+/// What a staged file actually contains, written beside it as `<name>.json`.
 ///
 /// A staged file is **not** necessarily valid whole-file content, and that is
 /// the whole reason this exists. A partial overwrite commits by filling the
@@ -365,6 +364,14 @@ pub struct StagedWrite {
    pub based_on: Option<Baseline>,
 }

+impl StagedWrite {
+    /// Whether `authored` ranges cover a file of `len` bytes, so the staged
+    /// bytes are its complete new content. An empty file has nothing to cover.
+    pub fn covers(authored: &[(u64, u64)], len: u64) -> bool {
+        len == 0 || authored == [(0, len)]
+    }
+}
+
 /// The identity of a remote revision, as far as we can observe it.
 ///
 /// `revision_id` is the authoritative identity when present: the server assigns a
@@ -431,9 +438,9 @@ pub struct ContentCache {
    /// Subdirectory for write-handle scratch files (disk-backed write buffers).
    /// Emptied on open so a crashed run leaves no orphans.
    scratch_dir: PathBuf,
-    /// Subdirectory holding the bytes of writes that have not been uploaded yet
-    /// (offline.md Phase 2/3) — every released write passes through here, since
-    /// the upload is a queued op performed later. Unlike `scratch_dir` this is
+    /// Subdirectory holding the bytes of writes that have not been uploaded yet.
+    /// Every released write passes through here, since the upload is a queued
+    /// op performed later. Unlike `scratch_dir` this is
    /// **never** emptied on open: these are the only copy of content the user
    /// authored, and the whole point is that they outlive the daemon.
    staging_dir: PathBuf,
@@ -468,7 +475,7 @@ pub struct ContentCache {
    thumb_bytes: AtomicU64,
    /// Unified metadata DB. Its `cache_entries` table is the LRU index: every
    /// store/read/evict updates it, and the budget enforcers query it instead of
-    /// scanning the cache directories (plan.md P4).
+    /// scanning the cache directories.
    db: Arc<Db>,
    /// LRU touches not yet written to `cache_entries`, keyed by cache key.
    ///
@@ -730,6 +737,60 @@ impl ContentCache {
        Some(buf)
    }

+    /// Write the whole content of `uid` at `(mtime, size)` to `dst` from the
+    /// cache alone, and report whether that worked.
+    ///
+    /// A whole-file blob is cloned. Otherwise every block of the revision has to
+    /// be cached, under its recorded geometry or, failing that, the uniform one
+    /// the read path would use. Anything short of the full content leaves
+    /// nothing at `dst`, so a caller falls back to a download with a clean slate.
+    ///
+    /// This is what lets a mirror folder take a file an on-demand mount has
+    /// already read, after a move between them, without fetching it again. The
+    /// trust is the read path's: the same `(mtime, size)` key, and blocks that
+    /// were validated when they were fetched.
+    pub fn copy_cached_to(&self, uid: &NodeUid, mtime: i64, size: u64, dst: &Path) -> bool {
+        if size == 0 {
+            return false;
+        }
+        if let Some(blob) = self.valid_blob(uid, mtime, size) {
+            if Self::clone_or_copy(&blob, dst).is_ok_and(|len| len == size) {
+                self.touch(Self::key(uid));
+                return true;
+            }
+            let _ = std::fs::remove_file(dst);
+            return false;
+        }
+        let geometry = self
+            .block_geometry(uid, mtime, size)
+            .unwrap_or_else(|| BlockGeometry::uniform(size));
+        if geometry.size() != size {
+            return false;
+        }
+        let spans = geometry.spans(0, size);
+        // Checked up front so a file with one block missing costs stats, not a
+        // copy of every block before it.
+        if !spans
+            .iter()
+            .all(|&span| self.has_block(uid, mtime, size, span))
+        {
+            return false;
+        }
+        let written = (|| -> Option<()> {
+            use std::io::Write;
+            let mut out = std::fs::File::create(dst).ok()?;
+            for span in spans {
+                out.write_all(&self.cached_block(uid, mtime, size, span)?)
+                    .ok()?;
+            }
+            (out.metadata().ok()?.len() == size).then_some(())
+        })();
+        if written.is_none() {
+            let _ = std::fs::remove_file(dst);
+        }
+        written.is_some()
+    }
+
    /// Store `bytes` as the cached content for `uid`, tagged with `(mtime,
    /// size)`. The blob is written to a temp file then renamed so a concurrent
    /// reader never sees a partial blob; the meta tag is written last so a
@@ -783,6 +844,9 @@ impl ContentCache {
        }
        let bytes = std::fs::metadata(&tmp)?.len();
        std::fs::rename(&tmp, &blob)?;
+        // Linked from the blob already cached, the temp name was a second name
+        // of it, and the rename did nothing (`docs/BUGS.md` B187).
+        let _ = std::fs::remove_file(&tmp);
        let meta = serde_json::to_vec(&Meta { mtime, size })?;
        std::fs::write(self.meta_path(uid), meta)?;
        self.db
@@ -924,7 +988,7 @@ impl ContentCache {
    /// a miss ([`cached_block`](Self::cached_block) checks), so a bad block
    /// cannot escape this cache even though this does not check. Validating a
    /// block is the *reader's* job, at the point it is fetched — see
-    /// `Core::read_block` (bugs.md B84).
+    /// `Core::read_block` (`docs/BUGS.md` B84).
    pub fn store_block(
        &self,
        uid: &NodeUid,
@@ -1426,9 +1490,8 @@ impl ContentCache {
    /// This is what makes a write survive its upload: the caller is releasing a
    /// write handle and would otherwise delete the file, so until the bytes are
    /// on the remote, staging holds the only copy. Every dirty handle goes
-    /// through here — the upload is a queued op performed later (offline.md
-    /// Phase 3), and a staged file is also what a human can recover from if the
-    /// queue never drains.
+    /// through here — the upload is a queued op performed later, and a staged
+    /// file is also what a human can recover from if the queue never drains.
    ///
    /// Falls back to a copy when the rename crosses a filesystem boundary; a
    /// failure here means we could not save the bytes at all, so it is reported
@@ -2002,6 +2065,17 @@ mod tests {
        NodeUid::new(VolumeId::from("vol"), LinkId::from(link))
    }

+    #[test]
+    fn an_empty_write_covers_the_file_and_a_gap_does_not() {
+        assert!(
+            StagedWrite::covers(&[], 0),
+            "an empty file has nothing to cover"
+        );
+        assert!(StagedWrite::covers(&[(0, 7)], 7));
+        assert!(!StagedWrite::covers(&[(0, 3), (4, 7)], 7));
+        assert!(!StagedWrite::covers(&[], 7));
+    }
+
    /// A unique temp directory removed on drop; avoids a dev-dependency.
    struct TempDir(PathBuf);
    impl TempDir {
@@ -2124,6 +2198,24 @@ mod tests {
        assert_eq!(c.read_range(&u, 200, 5, 0, 5).unwrap(), b"newer");
    }

+    /// A landed create and the revision after it can adopt the same staged
+    /// blob. The link to the temp name is then a second name of the cached
+    /// blob, and a rename between two names of one file does nothing: the
+    /// temp name stayed until the next start swept it (`docs/BUGS.md` B187).
+    #[test]
+    fn store_file_twice_from_the_same_blob_leaves_no_temp_file() {
+        let (c, d) = cache();
+        let u = uid("a");
+        let src = d.path().join("staged-blob");
+        std::fs::write(&src, b"staged").unwrap();
+
+        c.store_file(&u, 100, 6, &src).unwrap();
+        c.store_file(&u, 100, 6, &src).unwrap();
+
+        assert!(!c.blob_path(&u).with_extension("tmp").exists());
+        assert_eq!(c.read_range(&u, 100, 6, 0, 6).unwrap(), b"staged");
+    }
+
    #[test]
    fn reconcile_rebuilds_index_from_disk() {
        let dir = TempDir::new();
@@ -2561,6 +2653,46 @@ mod tests {
        assert!(c.cached_block(&u, 100, 5000, blk(5000, 0)).is_none());
    }

+    #[test]
+    fn a_cached_blob_is_copied_out_whole() {
+        let (c, d) = cache();
+        let u = uid("blob");
+        c.store(&u, 7, 5, b"hello").unwrap();
+        let dst = d.path().join("out");
+        assert!(c.copy_cached_to(&u, 7, 5, &dst));
+        assert_eq!(std::fs::read(&dst).unwrap(), b"hello");
+        // Another revision is not this one.
+        assert!(!c.copy_cached_to(&u, 8, 5, &d.path().join("stale")));
+        assert!(!d.path().join("stale").exists());
+    }
+
+    #[test]
+    fn cached_blocks_are_copied_out_in_order() {
+        let (c, d) = cache();
+        let u = uid("blocks");
+        let size = BLOCK_SIZE + 3;
+        let first = vec![1_u8; BLOCK_SIZE as usize];
+        c.store_block(&u, 7, size, blk(size, 0), &first).unwrap();
+        c.store_block(&u, 7, size, blk(size, 1), b"end").unwrap();
+        let dst = d.path().join("out");
+        assert!(c.copy_cached_to(&u, 7, size, &dst));
+        let bytes = std::fs::read(&dst).unwrap();
+        assert_eq!(bytes.len() as u64, size);
+        assert_eq!(&bytes[..BLOCK_SIZE as usize], first.as_slice());
+        assert_eq!(&bytes[BLOCK_SIZE as usize..], b"end");
+    }
+
+    #[test]
+    fn a_file_with_a_block_missing_is_not_copied_out() {
+        let (c, d) = cache();
+        let u = uid("partial");
+        let size = BLOCK_SIZE + 3;
+        c.store_block(&u, 7, size, blk(size, 1), b"end").unwrap();
+        let dst = d.path().join("out");
+        assert!(!c.copy_cached_to(&u, 7, size, &dst));
+        assert!(!dst.exists(), "a partial copy must not be left behind");
+    }
+
    /// The [`BlockSpan`] the uniform geometry gives block `idx` of a file of
    /// `size` bytes — the shape these tests were written against, and the one
    /// this client's own uploads still have.
@@ -2573,7 +2705,7 @@ mod tests {
    }

    /// The geometry the whole read path validates against, here and over the
-    /// network (bugs.md B84): full blocks, then whatever is left.
+    /// network (`docs/BUGS.md` B84): full blocks, then whatever is left.
    #[test]
    fn block_len_is_full_blocks_then_the_remainder() {
        let size = BLOCK_SIZE * 2 + 17;
@@ -2653,7 +2785,7 @@ mod tests {
    /// A cached block is addressed by the range it covers, not by its index
    /// alone. Re-planning a file onto its real geometry must therefore miss the
    /// blocks the uniform fallback cached, rather than serve their bytes at the
-    /// wrong offset (bugs.md B85).
+    /// wrong offset (`docs/BUGS.md` B85).
    #[test]
    fn a_cached_block_is_not_served_to_a_different_geometry() {
        let (c, _d) = cache();
@@ -2720,7 +2852,7 @@ mod tests {

    /// A block of the wrong length cannot escape the cache even though the
    /// store does not check: the read validates it and reports a miss, so the
-    /// next read refetches rather than serving a hole (bugs.md B84).
+    /// next read refetches rather than serving a hole (`docs/BUGS.md` B84).
    #[test]
    fn a_block_of_the_wrong_length_reads_as_a_miss() {
        let (c, _d) = cache();
@@ -2785,7 +2917,7 @@ mod tests {
        );
    }

-    /// A failed upload must never cost the user their bytes (offline.md Phase 2):
+    /// A failed upload must never cost the user their bytes:
    /// the scratch file moves to staging intact, and staging survives a reopen
    /// the way scratch deliberately does not.
    #[test]
@@ -154,6 +154,13 @@ pub struct AppConfig {
    /// configs predating the field.
    #[serde(default)]
    pub online_map: bool,
+    /// Record a new folder, a new file, a rename or a delete through the mount
+    /// locally and send it from the queue, instead of waiting for Drive in the
+    /// syscall. `None` means on. `false` brings back the old path for one
+    /// release (docs/ROADMAP.md). Defaulted for configs predating
+    /// the field.
+    #[serde(default)]
+    pub local_first: Option<bool>,
 }

 /// The My Files page's view choices, remembered between runs.
@@ -228,6 +235,7 @@ impl Default for AppConfig {
            tray_hidden: false,
            language: None,
            online_map: false,
+            local_first: None,
        }
    }
 }
@@ -424,7 +432,7 @@ impl AppDirs {
    /// typical umask makes them `0755`. Until this was fixed, the only thing
    /// keeping another local user out was `~/.cache` and `~/.local/state`
    /// happening to be `0700`, which is a convention of the user's system and
-    /// not something this client established (bugs.md B6).
+    /// not something this client established (`docs/BUGS.md` B6).
    ///
    /// Applied on every start, not just at creation: a directory that already
    /// exists with a permissive mode — restored from a backup that flattened
@@ -475,7 +483,7 @@ fn restrict_dir(dir: &Path) -> Result<()> {
 /// session — enumerate, read, upload, trash, share — without presenting any
 /// credential, since the daemon already holds one. It is an authority boundary,
 /// not merely private data, and `UnixListener::bind` applies the umask like any
-/// other file (bugs.md B6).
+/// other file (`docs/BUGS.md` B6).
 ///
 /// There is a window between `bind` and this call during which the socket
 /// carries the umask's mode. It is closed in practice by the containing
@@ -496,7 +504,7 @@ mod tests {
        std::fs::metadata(p).unwrap().permissions().mode() & 0o777
    }

-    /// bugs.md B6. A permissive mode here is not a cosmetic problem: these
+    /// `docs/BUGS.md` B6. A permissive mode here is not a cosmetic problem: these
    /// directories hold decrypted content, a plaintext index of every node name,
    /// and the control socket that commands the daemon's session.
    #[test]
@@ -584,6 +592,7 @@ mod tests {
            tray_hidden: true,
            language: Some("de".to_string()),
            online_map: true,
+            local_first: Some(false),
        };
        let json = serde_json::to_string(&config).unwrap();
        let decoded: AppConfig = serde_json::from_str(&json).unwrap();
@@ -339,7 +339,10 @@ pub enum Request {
    /// single path component (no separators). Replies with [`Response::Ok`].
    Rename { path: String, new_name: String },
    /// Move a file or folder into a new parent folder. Both `path` and
-    /// `new_parent` are mountpoint-relative. Replies with [`Response::Ok`].
+    /// `new_parent` are mountpoint-relative, or both absolute local paths; two
+    /// absolute paths may lie in different locations (My files, an on-demand
+    /// or a mirror synced folder), and the move is still made on Proton Drive
+    /// without transferring content. Replies with [`Response::Ok`].
    Move { path: String, new_parent: String },
    /// Trash a file or folder. `path` is mountpoint-relative. Replies with
    /// [`Response::Ok`].
@@ -440,11 +443,11 @@ pub enum Request {
    DeleteDevice { uid: String },
    /// Adopt an existing device as this machine's, pinning its uid in
    /// `config.json` so a hostname change or reinstall re-attaches to it instead
-    /// of registering a duplicate (features.md 5.1). `uid: None` clears the pin.
+    /// of registering a duplicate. `uid: None` clears the pin.
    /// Replies with [`Response::Ok`].
    AdoptDevice { uid: Option<String> },

-    // ---- device folder sync (devices.md) ----------------------------------
+    // ---- device folder sync ----------------------------------
    /// Add a local folder to this machine's device, uploading its tree and
    /// registering the device on first use. Replies with [`Response::Ok`].
    AddSyncFolder { local_path: String },
@@ -474,6 +477,15 @@ pub enum Request {
    /// Retry a backed-off queued op now instead of waiting out its backoff;
    /// every failed op when `id` is `None`. Replies with [`Response::Ok`].
    RetryPendingOp { id: Option<i64> },
+    /// Copy the content of a queued upload (`id` from
+    /// [`Request::ListPendingOps`]) to `dest`, an absolute path that must not
+    /// exist yet. The op stays queued. Replies with [`Response::Ok`].
+    ExportPendingOp { id: i64, dest: String },
+    /// Drop a queued change (`id` from [`Request::ListPendingOps`]) and undo
+    /// it locally: a node made here goes, a node Drive has goes back to what
+    /// Drive has, along with every other change queued on it. Its content is
+    /// lost unless it was exported first. Replies with [`Response::Ok`].
+    DiscardPendingOp { id: i64 },
    /// List the `(sync-conflict …)` copies under My Files and in synced
    /// folders. Replies with
    /// [`Response::Conflicts`].
@@ -484,7 +496,7 @@ pub enum Request {
    /// [`Response::Ok`].
    ResolveConflict { path: String, keep: ConflictKeep },
    /// List the folders under this machine's device that can be synced here,
-    /// each with a proposed local path (features.md 5.2). Replies with
+    /// each with a proposed local path. Replies with
    /// [`Response::RestorableFolders`].
    ListRestorableFolders,
    /// Attach the given remote device folders to local paths and sync them down.
@@ -877,6 +889,59 @@ pub struct PendingOpInfo {
    pub parked: bool,
    /// Failed often enough to count as stuck.
    pub failing: bool,
+    /// Why Drive refused it, when it did; such an op needs attention at once.
+    #[serde(default)]
+    pub issue: Option<SyncIssue>,
+    /// Carries file content that [`Request::ExportPendingOp`] can save.
+    #[serde(default)]
+    pub exportable: bool,
+}
+
+/// Why Drive refused a queued change (in [`PendingOpInfo`]). The change stays
+/// queued and keeps being retried; nothing is deleted.
+#[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq)]
+#[serde(rename_all = "snake_case")]
+pub enum SyncIssue {
+    /// The account's storage is full.
+    Quota,
+    /// The account may no longer change the file or its folder, for example
+    /// because a share was revoked.
+    Access,
+    /// The file or the folder it goes into is gone from Drive.
+    Missing,
+    /// The folder holds too many items, or is nested too deep.
+    Limit,
+    /// Drive rejected the change, for example a name it does not accept.
+    Rejected,
+    /// An issue from a newer daemon.
+    #[serde(other)]
+    Unknown,
+}
+
+impl SyncIssue {
+    /// The name stored in the database and sent on the wire.
+    pub fn as_str(self) -> &'static str {
+        match self {
+            SyncIssue::Quota => "quota",
+            SyncIssue::Access => "access",
+            SyncIssue::Missing => "missing",
+            SyncIssue::Limit => "limit",
+            SyncIssue::Rejected => "rejected",
+            SyncIssue::Unknown => "unknown",
+        }
+    }
+
+    /// The issue stored as `name`.
+    pub fn parse(name: &str) -> Self {
+        match name {
+            "quota" => SyncIssue::Quota,
+            "access" => SyncIssue::Access,
+            "missing" => SyncIssue::Missing,
+            "limit" => SyncIssue::Limit,
+            "rejected" => SyncIssue::Rejected,
+            _ => SyncIssue::Unknown,
+        }
+    }
 }

 /// One synced local folder on this machine's device (in [`Response::SyncFolders`]).
@@ -1231,6 +1296,10 @@ pub struct DirEntry {
    /// not known, and for anything not in the trash.
    #[serde(default)]
    pub trashed_from: Option<String>,
+    /// Why Drive refused a change queued on the node, for a [`Request::ListDir`]
+    /// entry; `None` otherwise.
+    #[serde(default)]
+    pub issue: Option<SyncIssue>,
 }

 /// One hit in a [`Request::Search`] result. Like [`DirEntry`] but carries the
@@ -1834,17 +1903,17 @@ pub enum Response {
        /// The pin registry.
        pins: Vec<Pin>,
        /// False when the daemon is serving the cached tree because the API is
-        /// unreachable (offline.md Phase 1). Cached and pinned content still
+        /// unreachable. Cached and pinned content still
        /// reads; anything else fails until the network is back.
        #[serde(default = "default_online")]
        online: bool,
-        /// Writes accepted locally but not yet uploaded (offline.md Phase 3).
+        /// Writes accepted locally but not yet uploaded.
        /// Non-zero means the mount is ahead of the remote — either a copy is
        /// still draining, or it cannot drain because we are offline.
        #[serde(default)]
        pending_uploads: u64,
-        /// Queued mutations that carry no bytes: `mkdir`, `rename`, `trash`
-        /// (offline.md Phase 3b). Counted apart from `pending_uploads` because
+        /// Queued mutations that carry no bytes: `mkdir`, `rename`, `trash`.
+        /// Counted apart from `pending_uploads` because
        /// calling a queued `mkdir` an upload is a lie.
        #[serde(default)]
        pending_changes: u64,
@@ -3287,6 +3356,17 @@ mod tests {
                },
                r#"{"SaveRevisionAsByUid":{"uid":"vol~link","revision_id":"rev-3","dest":"/tmp/out.bin"}}"#,
            ),
+            (
+                Request::ExportPendingOp {
+                    id: 7,
+                    dest: "/tmp/out.bin".into(),
+                },
+                r#"{"ExportPendingOp":{"id":7,"dest":"/tmp/out.bin"}}"#,
+            ),
+            (
+                Request::DiscardPendingOp { id: 7 },
+                r#"{"DiscardPendingOp":{"id":7}}"#,
+            ),
        ];
        for (request, wire) in cases {
            assert_eq!(serde_json::to_string(&request).unwrap(), wire);
@@ -3295,6 +3375,25 @@ mod tests {
        }
    }

+    /// A daemon that predates sync issues sends neither field, and a newer one
+    /// may send an issue this build does not know.
+    #[test]
+    fn a_queued_op_from_another_daemon_version_still_decodes() {
+        let old = r#"{"id":1,"kind":"create","path":"a.txt","attempts":0,"last_error":null,
+            "queued_at":5,"next_attempt_at":5,"parked":false,"failing":false}"#;
+        let op: PendingOpInfo = serde_json::from_str(old).unwrap();
+        assert_eq!(op.issue, None);
+        assert!(!op.exportable);
+
+        let newer = old.replace(r#""failing":false"#, r#""failing":true,"issue":"embargo""#);
+        let op: PendingOpInfo = serde_json::from_str(&newer).unwrap();
+        assert_eq!(op.issue, Some(SyncIssue::Unknown));
+        assert_eq!(
+            SyncIssue::parse(SyncIssue::Quota.as_str()),
+            SyncIssue::Quota
+        );
+    }
+
    /// A front-end that predates the favorites filter sends no `favorites`
    /// field, and must keep getting the whole timeline rather than an empty page.
    #[test]
@@ -0,0 +1,249 @@
+/* WARNING: Script requires that SQLITE_DBCONFIG_DEFENSIVE be disabled */
+PRAGMA foreign_keys=OFF;
+BEGIN TRANSACTION;
+CREATE TABLE sync_state (key TEXT PRIMARY KEY, value TEXT);
+INSERT INTO sync_state VALUES('schema_version','35');
+CREATE TABLE nodes (
+  uid           TEXT PRIMARY KEY,
+  parent_uid    TEXT,
+  name          TEXT NOT NULL,
+  is_dir        INTEGER NOT NULL,
+  size          INTEGER,
+  mtime         INTEGER NOT NULL,
+  revision_hash TEXT,
+  trashed       INTEGER NOT NULL DEFAULT 0
+, node_json TEXT, listed INTEGER NOT NULL DEFAULT 0, path TEXT);
+INSERT INTO nodes VALUES('vol~root',NULL,'My Files',1,0,200,NULL,0,'{"uid":{"volume_id":"vol","link_id":"root"},"parent_uid":null,"kind":"Folder","name":"My Files","creation_time":100,"modification_time":200,"trashed":false,"is_shared":false,"is_shared_publicly":false,"signature_email":null,"membership":null,"direct_role":null,"share_id":null,"photo":null,"album":null,"verification":{"name":"NotSigned","passphrase":"NotSigned","content_key":null,"extended_attributes":null}}',0,'');
+INSERT INTO nodes VALUES('vol~docs','vol~root','Docs',1,0,200,NULL,0,'{"uid":{"volume_id":"vol","link_id":"docs"},"parent_uid":{"volume_id":"vol","link_id":"root"},"kind":"Folder","name":"Docs","creation_time":100,"modification_time":200,"trashed":false,"is_shared":false,"is_shared_publicly":false,"signature_email":null,"membership":null,"direct_role":null,"share_id":null,"photo":null,"album":null,"verification":{"name":"NotSigned","passphrase":"NotSigned","content_key":null,"extended_attributes":null}}',0,'Docs');
+INSERT INTO nodes VALUES('vol~report','vol~docs','report.txt',0,10,200,NULL,0,'{"uid":{"volume_id":"vol","link_id":"report"},"parent_uid":{"volume_id":"vol","link_id":"docs"},"kind":{"File":{"media_type":"text/plain","total_size_on_storage":20,"active_revision_state":null,"active_revision_id":null,"claimed_size":10,"claimed_modification_time":null,"content_sha1":null}},"name":"report.txt","creation_time":100,"modification_time":200,"trashed":false,"is_shared":false,"is_shared_publicly":false,"signature_email":null,"membership":null,"direct_role":null,"share_id":null,"photo":null,"album":null,"verification":{"name":"NotSigned","passphrase":"NotSigned","content_key":null,"extended_attributes":null}}',0,'Docs/report.txt');
+INSERT INTO nodes VALUES('vol~old','vol~docs','old.txt',0,3,200,NULL,0,'{"uid":{"volume_id":"vol","link_id":"old"},"parent_uid":{"volume_id":"vol","link_id":"docs"},"kind":{"File":{"media_type":"text/plain","total_size_on_storage":13,"active_revision_state":null,"active_revision_id":null,"claimed_size":3,"claimed_modification_time":null,"content_sha1":null}},"name":"old.txt","creation_time":100,"modification_time":200,"trashed":false,"is_shared":false,"is_shared_publicly":false,"signature_email":null,"membership":null,"direct_role":null,"share_id":null,"photo":null,"album":null,"verification":{"name":"NotSigned","passphrase":"NotSigned","content_key":null,"extended_attributes":null}}',0,'Docs/old.txt');
+INSERT INTO nodes VALUES('vol~shared','vol~docs','shared.txt',0,4,200,NULL,0,'{"uid":{"volume_id":"vol","link_id":"shared"},"parent_uid":{"volume_id":"vol","link_id":"docs"},"kind":{"File":{"media_type":"text/plain","total_size_on_storage":14,"active_revision_state":null,"active_revision_id":null,"claimed_size":4,"claimed_modification_time":null,"content_sha1":null}},"name":"shared.txt","creation_time":100,"modification_time":200,"trashed":false,"is_shared":false,"is_shared_publicly":false,"signature_email":null,"membership":null,"direct_role":null,"share_id":null,"photo":null,"album":null,"verification":{"name":"NotSigned","passphrase":"NotSigned","content_key":null,"extended_attributes":null}}',0,'Docs/shared.txt');
+INSERT INTO nodes VALUES('local~dir','vol~root','Offline folder',1,0,200,NULL,0,'{"uid":{"volume_id":"local","link_id":"dir"},"parent_uid":{"volume_id":"vol","link_id":"root"},"kind":"Folder","name":"Offline folder","creation_time":100,"modification_time":200,"trashed":false,"is_shared":false,"is_shared_publicly":false,"signature_email":null,"membership":null,"direct_role":null,"share_id":null,"photo":null,"album":null,"verification":{"name":"NotSigned","passphrase":"NotSigned","content_key":null,"extended_attributes":null}}',1,'Offline folder');
+INSERT INTO nodes VALUES('local~inner','local~dir','inner.txt',0,5,200,NULL,0,'{"uid":{"volume_id":"local","link_id":"inner"},"parent_uid":{"volume_id":"local","link_id":"dir"},"kind":{"File":{"media_type":"text/plain","total_size_on_storage":15,"active_revision_state":null,"active_revision_id":null,"claimed_size":5,"claimed_modification_time":null,"content_sha1":null}},"name":"inner.txt","creation_time":100,"modification_time":200,"trashed":false,"is_shared":false,"is_shared_publicly":false,"signature_email":null,"membership":null,"direct_role":null,"share_id":null,"photo":null,"album":null,"verification":{"name":"NotSigned","passphrase":"NotSigned","content_key":null,"extended_attributes":null}}',0,'Offline folder/inner.txt');
+INSERT INTO nodes VALUES('local~part','vol~root','movie.part',0,7,200,NULL,0,'{"uid":{"volume_id":"local","link_id":"part"},"parent_uid":{"volume_id":"vol","link_id":"root"},"kind":{"File":{"media_type":"text/plain","total_size_on_storage":17,"active_revision_state":null,"active_revision_id":null,"claimed_size":7,"claimed_modification_time":null,"content_sha1":null}},"name":"movie.part","creation_time":100,"modification_time":200,"trashed":false,"is_shared":false,"is_shared_publicly":false,"signature_email":null,"membership":null,"direct_role":null,"share_id":null,"photo":null,"album":null,"verification":{"name":"NotSigned","passphrase":"NotSigned","content_key":null,"extended_attributes":null}}',0,'movie.part');
+CREATE TABLE cache_entries (
+  cache_key     TEXT PRIMARY KEY,
+  size_bytes    INTEGER,
+  last_accessed INTEGER,
+  is_pinned     INTEGER NOT NULL DEFAULT 0
+, kind TEXT NOT NULL DEFAULT 'blob');
+CREATE TABLE pins (
+  uid       TEXT PRIMARY KEY,
+  path      TEXT NOT NULL,
+  recursive INTEGER NOT NULL DEFAULT 0
+);
+CREATE TABLE local_files (
+  id       INTEGER PRIMARY KEY,
+  path     TEXT NOT NULL UNIQUE,
+  name     TEXT NOT NULL,
+  is_dir   INTEGER NOT NULL,
+  size     INTEGER NOT NULL DEFAULT 0,
+  mtime    INTEGER NOT NULL DEFAULT 0,
+  scan_gen INTEGER NOT NULL DEFAULT 0
+);
+CREATE TABLE photos (
+  uid          TEXT PRIMARY KEY,
+  capture_time INTEGER NOT NULL,
+  name         TEXT,
+  ratio        REAL,
+  thumb_state  INTEGER NOT NULL DEFAULT 0,
+  seq          INTEGER NOT NULL
+, media_type TEXT, kind INTEGER NOT NULL DEFAULT 0, favorite INTEGER NOT NULL DEFAULT 0, content_hash TEXT, main_uid TEXT, group_key TEXT, resolved_at INTEGER, latitude REAL, longitude REAL, place_id INTEGER, similar_hash INTEGER);
+CREATE TABLE trash (
+  uid    TEXT PRIMARY KEY,
+  name   TEXT NOT NULL,
+  is_dir INTEGER NOT NULL,
+  size   INTEGER NOT NULL DEFAULT 0,
+  mtime  INTEGER NOT NULL DEFAULT 0
+, parent_uid TEXT, trashed_at INTEGER);
+CREATE TABLE device (
+  uid      TEXT PRIMARY KEY,
+  share_id TEXT NOT NULL,
+  root_uid TEXT NOT NULL,
+  name     TEXT NOT NULL,
+  created  INTEGER NOT NULL DEFAULT 0
+);
+CREATE TABLE sync_folder (
+  id              INTEGER PRIMARY KEY,
+  local_path      TEXT NOT NULL UNIQUE,
+  remote_uid      TEXT NOT NULL,
+  remote_share_id TEXT NOT NULL,
+  mode            TEXT NOT NULL DEFAULT 'mirror',
+  state           TEXT NOT NULL DEFAULT 'idle',
+  last_sync       INTEGER NOT NULL DEFAULT 0
+, pending_mode TEXT);
+CREATE TABLE sync_entry (
+  folder_id   INTEGER NOT NULL,
+  rel_path    TEXT NOT NULL,
+  remote_uid  TEXT,
+  local_mtime INTEGER NOT NULL DEFAULT 0,
+  local_size  INTEGER NOT NULL DEFAULT 0,
+  remote_hash TEXT,
+  remote_rev  TEXT, local_mtime_ns INTEGER,
+  PRIMARY KEY (folder_id, rel_path)
+);
+CREATE TABLE activity (
+  id     INTEGER PRIMARY KEY,
+  time   INTEGER NOT NULL,
+  kind   TEXT NOT NULL,
+  target TEXT NOT NULL,
+  detail TEXT NOT NULL DEFAULT '',
+  ok     INTEGER NOT NULL DEFAULT 1
+);
+CREATE TABLE pending_op (
+  id              INTEGER PRIMARY KEY,
+  kind            TEXT NOT NULL,
+  uid             TEXT NOT NULL,
+  blob_path       TEXT,
+  meta_json       TEXT,
+  created_at      INTEGER NOT NULL,
+  attempts        INTEGER NOT NULL DEFAULT 0,
+  last_error      TEXT,
+  next_attempt_at INTEGER NOT NULL DEFAULT 0
+, parent_uid TEXT, name TEXT, claimed_at INTEGER NOT NULL DEFAULT 0, access_deferred_since INTEGER NOT NULL DEFAULT 0);
+INSERT INTO pending_op VALUES(1,'mkdir','local~dir',NULL,NULL,1700000000000,0,NULL,0,'vol~root','Offline folder',4611686018427387903,0);
+INSERT INTO pending_op VALUES(2,'create','local~inner','/blobs/inner','{"len":5,"mtime":1700000000,"based_on":null}',1700000000000,0,NULL,0,'local~dir','inner.txt',0,0);
+INSERT INTO pending_op VALUES(3,'create','local~part','/blobs/part','{"len":5,"mtime":1700000000,"based_on":null}',1700000000000,0,NULL,8000000000000,'vol~root','movie.part',0,0);
+INSERT INTO pending_op VALUES(4,'revision','vol~report','/blobs/report','{"len":5,"mtime":1700000000,"based_on":null}',1700000000000,2,'network unreachable',1700000900000,NULL,NULL,0,0);
+INSERT INTO pending_op VALUES(5,'rename','vol~shared',NULL,'{"original_parent_uid":"vol~docs","original_name":"shared.txt"}',1700000000000,0,NULL,1700000700000,'vol~root','shared-moved.txt',0,1700000100000);
+INSERT INTO pending_op VALUES(6,'trash','vol~old',NULL,NULL,1700000000000,0,NULL,0,NULL,NULL,0,0);
+CREATE TABLE IF NOT EXISTS 'local_fts_data'(id INTEGER PRIMARY KEY, block BLOB);
+INSERT INTO local_fts_data VALUES(1,x'000000');
+INSERT INTO local_fts_data VALUES(10,x'00000000000000');
+CREATE TABLE IF NOT EXISTS 'local_fts_idx'(segid, term, pgno, PRIMARY KEY(segid, term)) WITHOUT ROWID;
+CREATE TABLE IF NOT EXISTS 'local_fts_docsize'(id INTEGER PRIMARY KEY, sz BLOB);
+CREATE TABLE IF NOT EXISTS 'local_fts_config'(k PRIMARY KEY, v) WITHOUT ROWID;
+INSERT INTO local_fts_config VALUES('version',4);
+CREATE TABLE share_access (
+  root_uid TEXT PRIMARY KEY,
+  access   TEXT NOT NULL
+           CHECK (access IN ('owner', 'editor', 'viewer', 'unknown'))
+);
+CREATE TABLE mount (
+  id              INTEGER PRIMARY KEY,
+  kind            TEXT NOT NULL
+                  CHECK (kind IN ('myfiles', 'device', 'shared')),
+  sync_folder_id  INTEGER REFERENCES sync_folder(id) ON DELETE CASCADE,
+  share_root_uid  TEXT,
+  local_path      TEXT NOT NULL DEFAULT '',
+  root_uid        TEXT NOT NULL DEFAULT '',
+  root_share_id   TEXT NOT NULL DEFAULT '',
+  mode            TEXT NOT NULL DEFAULT 'unknown',
+  access          TEXT NOT NULL DEFAULT 'rw'
+                  CHECK (access IN ('rw', 'ro')),
+  CHECK (
+    (kind = 'myfiles' AND sync_folder_id IS NULL AND share_root_uid IS NULL)
+    OR
+    (kind = 'device' AND sync_folder_id IS NOT NULL AND share_root_uid IS NULL)
+    OR
+    (kind = 'shared' AND sync_folder_id IS NULL AND share_root_uid IS NOT NULL)
+  )
+);
+CREATE TABLE albums (
+  uid           TEXT PRIMARY KEY,
+  name          TEXT NOT NULL,
+  photo_count   INTEGER NOT NULL DEFAULT 0,
+  cover_uid     TEXT,
+  last_activity INTEGER,
+  shared        INTEGER NOT NULL DEFAULT 0,
+  seq           INTEGER NOT NULL
+);
+CREATE TABLE album_photos (
+  album_uid    TEXT NOT NULL,
+  uid          TEXT NOT NULL,
+  capture_time INTEGER NOT NULL,
+  name         TEXT,
+  media_type   TEXT,
+  kind         INTEGER NOT NULL DEFAULT 0,
+  ratio        REAL,
+  thumb_state  INTEGER NOT NULL DEFAULT 0,
+  seq          INTEGER NOT NULL,
+  PRIMARY KEY (album_uid, uid)
+);
+CREATE TABLE IF NOT EXISTS 'nodes_fts_data'(id INTEGER PRIMARY KEY, block BLOB);
+INSERT INTO nodes_fts_data VALUES(1,x'083850');
+INSERT INTO nodes_fts_data VALUES(10,x'000000000108080008010101020101030101040101050101060101070101080101');
+INSERT INTO nodes_fts_data VALUES(137438953473,x'000000340430206669010204010366696c0102050103696c6501020601036c657301020701036d79200102020103792066010203040808080808');
+INSERT INTO nodes_fts_data VALUES(274877906945,x'0000001a0430646f6302080201010201036f6373020803010103040b');
+INSERT INTO nodes_fts_data VALUES(412316860417,x'0000008b04302e747803080801010d01032f72650306010106010363732f03060101040103646f630306010102010365706f03080301010801036f637303060101030202727403080501010a0103706f7203080401010901037265700308020101070202742e03080601010b0103732f7203060101050103742e7403080701010c0202787403080901010e040b0a0a0a0b0a0a0b0b0a0a0b');
+INSERT INTO nodes_fts_data VALUES(549755813889,x'0000006b04302e747804080501010a01032f6f6c0406010106010363732f04060101040103642e7404080401010902026f63040601010201036c642e04080301010801036f6373040601010302026c640408020101070103732f6f0406010105010374787404080601010b040b0a0a0b090b0a0a0a');
+INSERT INTO nodes_fts_data VALUES(687194767361,x'0000008c04302e747805080801010d01032f736805060101060103617265050804010109010363732f05060101040103642e7405080701010c02026f630506010102010365642e05080601010b010368617205080301010801036f63730506010103010372656405080501010a0103732f73050601010502026861050802010107010374787405080901010e040b0a0b0a0b090b0b0a0b0a0a');
+INSERT INTO nodes_fts_data VALUES(824633720833,x'00000084043020666f060809010109010364657206080d01010d0103652066060808010108010366666c06080301010302026c6906080401010402026f6c06080a01010a0103696e6506080601010601036c646506080c01010c0202696e06080501010501036e652006080701010701036f666606080201010202026c6406080b01010b040b0b0b0b0a0a0b0b0a0b0b');
+INSERT INTO nodes_fts_data VALUES(962072674305,x'000000da043020666f070601010901032e747807080701011601032f696e07060101100103646572070601010d010365206607060101080202722e07080501011403012f070601010e010366666c070601010302026c69070601010402026f6c070601010a0103696e65070601010603016e07080201011101036c6465070601010c0202696e070601010501036e6520070601010703017207080401011302026e6507080301011201036f6666070601010202026c64070601010b0103722e7407080601011502022f69070601010f0103747874070808010117040a0b0a0a0a0a080a09090a090a090a090a0a090b09');
+INSERT INTO nodes_fts_data VALUES(1099511627777,x'0000005c04302e706108080701010701036172740808090101090103652e70080806010106010369652e08080501010501036d6f7608080201010201036f766908080301010301037061720808080101080103766965080804010104040b0b0b0b0b0b0b');
+CREATE TABLE IF NOT EXISTS 'nodes_fts_idx'(segid, term, pgno, PRIMARY KEY(segid, term)) WITHOUT ROWID;
+INSERT INTO nodes_fts_idx VALUES(1,x'',2);
+INSERT INTO nodes_fts_idx VALUES(2,x'',2);
+INSERT INTO nodes_fts_idx VALUES(3,x'',2);
+INSERT INTO nodes_fts_idx VALUES(4,x'',2);
+INSERT INTO nodes_fts_idx VALUES(5,x'',2);
+INSERT INTO nodes_fts_idx VALUES(6,x'',2);
+INSERT INTO nodes_fts_idx VALUES(7,x'',2);
+INSERT INTO nodes_fts_idx VALUES(8,x'',2);
+CREATE TABLE IF NOT EXISTS 'nodes_fts_content'(id INTEGER PRIMARY KEY, c0, c1);
+INSERT INTO nodes_fts_content VALUES(1,'My Files','');
+INSERT INTO nodes_fts_content VALUES(2,'Docs','Docs');
+INSERT INTO nodes_fts_content VALUES(3,'report.txt','Docs/report.txt');
+INSERT INTO nodes_fts_content VALUES(4,'old.txt','Docs/old.txt');
+INSERT INTO nodes_fts_content VALUES(5,'shared.txt','Docs/shared.txt');
+INSERT INTO nodes_fts_content VALUES(6,'Offline folder','Offline folder');
+INSERT INTO nodes_fts_content VALUES(7,'inner.txt','Offline folder/inner.txt');
+INSERT INTO nodes_fts_content VALUES(8,'movie.part','movie.part');
+CREATE TABLE IF NOT EXISTS 'nodes_fts_docsize'(id INTEGER PRIMARY KEY, sz BLOB);
+INSERT INTO nodes_fts_docsize VALUES(1,x'0600');
+INSERT INTO nodes_fts_docsize VALUES(2,x'0202');
+INSERT INTO nodes_fts_docsize VALUES(3,x'080d');
+INSERT INTO nodes_fts_docsize VALUES(4,x'050a');
+INSERT INTO nodes_fts_docsize VALUES(5,x'080d');
+INSERT INTO nodes_fts_docsize VALUES(6,x'0c0c');
+INSERT INTO nodes_fts_docsize VALUES(7,x'0716');
+INSERT INTO nodes_fts_docsize VALUES(8,x'0808');
+CREATE TABLE IF NOT EXISTS 'nodes_fts_config'(k PRIMARY KEY, v) WITHOUT ROWID;
+INSERT INTO nodes_fts_config VALUES('version',4);
+CREATE TABLE own_sealed_rev (
+  uid         TEXT PRIMARY KEY,
+  revision_id TEXT NOT NULL,
+  sealed_at   INTEGER NOT NULL
+);
+INSERT INTO own_sealed_rev VALUES('vol~report','rev-1',1700000000000);
+PRAGMA writable_schema=ON;
+INSERT INTO sqlite_schema(type,name,tbl_name,rootpage,sql)VALUES('table','local_fts','local_fts',0,'CREATE VIRTUAL TABLE local_fts USING fts5(
+  name, path, content=''local_files'', content_rowid=''id'', tokenize=''trigram''
+)');
+INSERT INTO sqlite_schema(type,name,tbl_name,rootpage,sql)VALUES('table','nodes_fts','nodes_fts',0,'CREATE VIRTUAL TABLE nodes_fts USING fts5(
+  name, path, tokenize=''trigram''
+)');
+CREATE TRIGGER mount_sync_folder_insert
+AFTER INSERT ON sync_folder
+BEGIN
+  INSERT OR IGNORE INTO mount (kind, sync_folder_id)
+  VALUES ('device', NEW.id);
+END;
+CREATE INDEX idx_nodes_parent ON nodes(parent_uid);
+CREATE INDEX idx_photos_seq ON photos(seq);
+CREATE INDEX pending_op_uid ON pending_op(uid);
+CREATE INDEX pending_op_parent ON pending_op(parent_uid);
+CREATE INDEX cache_entries_lru ON cache_entries(kind, last_accessed);
+CREATE INDEX idx_nodes_name_nocase ON nodes(name COLLATE NOCASE);
+CREATE INDEX idx_local_files_name_nocase
+  ON local_files(name COLLATE NOCASE);
+CREATE UNIQUE INDEX mount_myfiles
+  ON mount(kind) WHERE kind = 'myfiles';
+CREATE UNIQUE INDEX mount_device
+  ON mount(sync_folder_id) WHERE kind = 'device';
+CREATE UNIQUE INDEX mount_shared
+  ON mount(share_root_uid) WHERE kind = 'shared';
+CREATE INDEX idx_album_photos_seq ON album_photos(album_uid, seq);
+CREATE INDEX idx_album_photos_uid ON album_photos(uid);
+CREATE INDEX idx_photos_favorite ON photos(favorite, seq);
+CREATE INDEX idx_sync_entry_remote_uid ON sync_entry(remote_uid);
+CREATE INDEX idx_local_files_scan_gen ON local_files(scan_gen);
+CREATE INDEX idx_nodes_parent_live ON nodes(parent_uid) WHERE trashed = 0;
+CREATE INDEX idx_pending_op_claimed
+    ON pending_op(uid) WHERE claimed_at <> 0;
+CREATE INDEX idx_trash_parent ON trash(parent_uid);
+CREATE INDEX idx_photos_group ON photos(group_key);
+CREATE INDEX idx_photos_unresolved ON photos(resolved_at);
+CREATE INDEX idx_photos_place ON photos(place_id);
+PRAGMA writable_schema=OFF;
+COMMIT;
@@ -1,4 +1,4 @@
-//! Database health reporting and repair (features.md 4.3).
+//! Database health reporting and repair.
 //!
 //! Everything here exists for the case where something has already gone wrong:
 //! a crash mid-write, a full disk, a cache that has grown out of proportion to
@@ -5,11 +5,13 @@
 //! is already on disk somewhere, so a change here would silently diverge from
 //! what an existing install actually has. Add a new one instead.

+use rusqlite::OptionalExtension;
+
 use super::Db;
 use crate::Result;

 /// Current schema version. Bump on every forward migration added below.
-pub(super) const SCHEMA_VERSION: i64 = 35;
+pub(super) const SCHEMA_VERSION: i64 = 42;

 impl Db {
    pub(super) fn migrate(&self) -> Result<()> {
@@ -332,6 +334,112 @@ impl Db {
                tx.execute_batch(MIGRATION_V35)?;
            }
        }
+        if current < 36 {
+            // Same guards as V26-V35.
+            let has_column: bool = tx.query_row(
+                "SELECT COUNT(*) FROM pragma_table_info('nodes') WHERE name = 'lid'",
+                [],
+                |row| row.get::<_, i64>(0),
+            )? > 0;
+            let has_nodes: bool = tx.query_row(
+                "SELECT COUNT(*) FROM sqlite_master WHERE type = 'table' AND name = 'nodes'",
+                [],
+                |row| row.get::<_, i64>(0),
+            )? > 0;
+            if has_nodes && !has_column {
+                tx.execute_batch(MIGRATION_V36)?;
+            }
+        }
+        if current < 37 {
+            // Same guards as V26-V36.
+            let sql: Option<String> = tx
+                .query_row(
+                    "SELECT sql FROM sqlite_master WHERE type = 'table' AND name = 'pending_op'",
+                    [],
+                    |row| row.get(0),
+                )
+                .optional()?;
+            if sql.is_some_and(|sql| !sql.contains("AUTOINCREMENT")) {
+                tx.execute_batch(MIGRATION_V37)?;
+            }
+        }
+        if current < 38 {
+            // Same guards as V26-V37.
+            let has_column: bool = tx.query_row(
+                "SELECT COUNT(*) FROM pragma_table_info('pending_op') WHERE name = 'issue'",
+                [],
+                |row| row.get::<_, i64>(0),
+            )? > 0;
+            let has_ops: bool = tx.query_row(
+                "SELECT COUNT(*) FROM sqlite_master WHERE type = 'table' AND name = 'pending_op'",
+                [],
+                |row| row.get::<_, i64>(0),
+            )? > 0;
+            if has_ops && !has_column {
+                tx.execute_batch(MIGRATION_V38)?;
+            }
+        }
+        if current < 39 {
+            // Same guards as V26-V38.
+            let has_column: bool = tx.query_row(
+                "SELECT COUNT(*) FROM pragma_table_info('pending_op') WHERE name = 'lid'",
+                [],
+                |row| row.get::<_, i64>(0),
+            )? > 0;
+            let has_ops: bool = tx.query_row(
+                "SELECT COUNT(*) FROM sqlite_master WHERE type = 'table' AND name = 'pending_op'",
+                [],
+                |row| row.get::<_, i64>(0),
+            )? > 0;
+            if has_ops && !has_column {
+                tx.execute_batch(MIGRATION_V39)?;
+            }
+        }
+        if current < 40 {
+            // Same guards as V26-V39.
+            let has_column: bool = tx.query_row(
+                "SELECT COUNT(*) FROM pragma_table_info('nodes') WHERE name = 'parent_lid'",
+                [],
+                |row| row.get::<_, i64>(0),
+            )? > 0;
+            let has_nodes: bool = tx.query_row(
+                "SELECT COUNT(*) FROM sqlite_master WHERE type = 'table' AND name = 'nodes'",
+                [],
+                |row| row.get::<_, i64>(0),
+            )? > 0;
+            if has_nodes && !has_column {
+                tx.execute_batch(MIGRATION_V40)?;
+            }
+        }
+        if current < 41 {
+            // Needs both tables; on a database that never had them there is
+            // nothing to rewrite.
+            let tables: i64 = tx.query_row(
+                "SELECT COUNT(*) FROM sqlite_master
+                 WHERE type = 'table' AND name IN ('nodes', 'pending_op', 'pins')",
+                [],
+                |row| row.get(0),
+            )?;
+            if tables == 3 {
+                tx.execute_batch(MIGRATION_V41)?;
+            }
+        }
+        if current < 42 {
+            // Same guards as V26-V40.
+            let has_column: bool = tx.query_row(
+                "SELECT COUNT(*) FROM pragma_table_info('pending_op') WHERE name = 'sent_sha1'",
+                [],
+                |row| row.get::<_, i64>(0),
+            )? > 0;
+            let has_ops: bool = tx.query_row(
+                "SELECT COUNT(*) FROM sqlite_master WHERE type = 'table' AND name = 'pending_op'",
+                [],
+                |row| row.get::<_, i64>(0),
+            )? > 0;
+            if has_ops && !has_column {
+                tx.execute_batch(MIGRATION_V42)?;
+            }
+        }
        tx.execute(
            "INSERT INTO sync_state (key, value) VALUES ('schema_version', ?1)
             ON CONFLICT(key) DO UPDATE SET value = excluded.value",
@@ -469,7 +577,7 @@ CREATE TABLE trash (
 );
 ";

-/// Schema v8: device sync (devices.md). This machine registers as one Proton Drive
+/// Schema v8: device sync. This machine registers as one Proton Drive
 /// **Device** (a share + root folder on the main volume); `device` is a singleton
 /// row cached so we reuse the same device across restarts instead of creating a
 /// new one each run. `sync_folder` is one row per local folder the user added,
@@ -530,8 +638,8 @@ ALTER TABLE sync_folder ADD COLUMN pending_mode TEXT;
 ";

 /// Schema v11: writes no longer upload inside the FUSE handler. `release` stages
-/// the bytes and records the intended upload here, and a drain worker performs it
-/// (offline.md Phase 3). The row outlives the process, so a write survives both a
+/// the bytes and records the intended upload here, and a drain worker performs it.
+/// The row outlives the process, so a write survives both a
 /// dead network and a restart.
 ///
 /// `blob_path` points into the content cache's `staging/` dir and `meta_json` is
@@ -558,7 +666,7 @@ CREATE INDEX pending_op_uid ON pending_op(uid);

 /// Schema v12: `pending_op` also carries mutations that *create* a node, which a
 /// revision op never had to describe — it always addressed a node the server had
-/// already minted a uid for (offline.md Phase 3b).
+/// already minted a uid for.
 ///
 /// An offline `create`/`mkdir` cannot get a real uid, so the node is invented
 /// locally under a `local~<uuid>` placeholder and the op records where it goes
@@ -948,7 +1056,7 @@ ALTER TABLE pending_op ADD COLUMN access_deferred_since INTEGER NOT NULL DEFAULT
 /// as the last sync and left the file the same length — a fixed-size record
 /// rewritten, an image re-exported, a database page updated in place — read as
 /// *unchanged* and was never uploaded. The remote copy silently stayed at the
-/// older content until something else about the file moved (bugs.md B25).
+/// older content until something else about the file moved (`docs/BUGS.md` B25).
 ///
 /// Nullable rather than a converted `local_mtime * 1_000_000_000`: the
 /// nanosecond part of an existing baseline is genuinely unknown, and inventing
@@ -1059,3 +1167,166 @@ ALTER TABLE photos ADD COLUMN similar_hash INTEGER;
 const MIGRATION_V35: &str = "
 ALTER TABLE trash ADD COLUMN trashed_at INTEGER;
 ";
+
+/// Schema v36: every node row has a local id (`lid`); see
+/// docs/ARCHITECTURE.md §2.
+///
+/// The `uid` was the row's key, so a node had no identity until Drive minted
+/// one, and a create that landed moved its row to a new key. The `lid` is given
+/// when the row is first written and never changes or comes back, which is what
+/// `AUTOINCREMENT` adds over a plain rowid. It takes the old rowid, so the
+/// search index, keyed by rowid since v15, stays valid. The `uid` becomes
+/// nullable for a node that is not on Drive yet.
+const MIGRATION_V36: &str = "
+CREATE TABLE nodes_v36 (
+  lid           INTEGER PRIMARY KEY AUTOINCREMENT,
+  uid           TEXT UNIQUE,
+  parent_uid    TEXT,
+  name          TEXT NOT NULL,
+  is_dir        INTEGER NOT NULL,
+  size          INTEGER,
+  mtime         INTEGER NOT NULL,
+  revision_hash TEXT,
+  trashed       INTEGER NOT NULL DEFAULT 0,
+  node_json     TEXT,
+  listed        INTEGER NOT NULL DEFAULT 0,
+  path          TEXT
+);
+INSERT INTO nodes_v36
+  (lid, uid, parent_uid, name, is_dir, size, mtime, revision_hash, trashed, node_json, listed,
+   path)
+  SELECT rowid, uid, parent_uid, name, is_dir, size, mtime, revision_hash, trashed, node_json,
+         listed, path
+    FROM nodes;
+DROP TABLE nodes;
+ALTER TABLE nodes_v36 RENAME TO nodes;
+CREATE INDEX idx_nodes_parent ON nodes(parent_uid);
+CREATE INDEX idx_nodes_name_nocase ON nodes(name COLLATE NOCASE);
+CREATE INDEX idx_nodes_parent_live ON nodes(parent_uid) WHERE trashed = 0;
+";
+
+/// Schema v37: a `pending_op` id is never given out twice.
+///
+/// A plain rowid is the largest one plus one, so an op queued right after the
+/// newest one was dropped took its id. The drain retires the op it is
+/// working on by id, and so deleted the new op: a trash queued over a rename
+/// on the wire was lost when the rename landed. `AUTOINCREMENT` never reuses
+/// an id. Ids are kept, as is every index.
+const MIGRATION_V37: &str = "
+CREATE TABLE pending_op_v37 (
+  id                    INTEGER PRIMARY KEY AUTOINCREMENT,
+  kind                  TEXT NOT NULL,
+  uid                   TEXT NOT NULL,
+  blob_path             TEXT,
+  meta_json             TEXT,
+  created_at            INTEGER NOT NULL,
+  attempts              INTEGER NOT NULL DEFAULT 0,
+  last_error            TEXT,
+  next_attempt_at       INTEGER NOT NULL DEFAULT 0,
+  parent_uid            TEXT,
+  name                  TEXT,
+  claimed_at            INTEGER NOT NULL DEFAULT 0,
+  access_deferred_since INTEGER NOT NULL DEFAULT 0
+);
+INSERT INTO pending_op_v37
+  (id, kind, uid, blob_path, meta_json, created_at, attempts, last_error, next_attempt_at,
+   parent_uid, name, claimed_at, access_deferred_since)
+  SELECT id, kind, uid, blob_path, meta_json, created_at, attempts, last_error,
+         next_attempt_at, parent_uid, name, claimed_at, access_deferred_since
+    FROM pending_op;
+DROP TABLE pending_op;
+ALTER TABLE pending_op_v37 RENAME TO pending_op;
+CREATE INDEX pending_op_uid ON pending_op(uid);
+CREATE INDEX pending_op_parent ON pending_op(parent_uid);
+CREATE INDEX idx_pending_op_claimed
+    ON pending_op(uid) WHERE claimed_at <> 0;
+";
+
+/// Schema v38: why Drive refused a queued op, when it did (a sync issue).
+/// `NULL` for an op that has not been refused, which is every op migrated.
+const MIGRATION_V38: &str = "
+ALTER TABLE pending_op ADD COLUMN issue TEXT;
+";
+
+/// Schema v39: a queued op names its node and its parent by local id too.
+///
+/// A create made inside a folder that had not landed named the folder by its
+/// placeholder uid, and every landing had to find and rewrite those strings.
+/// The local id stays the same when the folder lands. An op whose node has no
+/// row keeps `NULL` and is matched by uid, as before.
+const MIGRATION_V39: &str = "
+ALTER TABLE pending_op ADD COLUMN lid INTEGER;
+ALTER TABLE pending_op ADD COLUMN parent_lid INTEGER;
+UPDATE pending_op
+   SET lid = (SELECT lid FROM nodes WHERE nodes.uid = pending_op.uid),
+       parent_lid = (SELECT lid FROM nodes WHERE nodes.uid = pending_op.parent_uid);
+CREATE INDEX pending_op_lid ON pending_op(lid);
+CREATE INDEX pending_op_parent_lid ON pending_op(parent_lid);
+";
+
+/// Schema v40: a node row names its parent by local id too.
+///
+/// The local id stays when a folder made here lands and its row takes the uid
+/// Drive gave it, so a child linked by it needs no rewrite. `NULL` while the
+/// parent has no row, as `parent_uid` then names nothing either.
+const MIGRATION_V40: &str = "
+ALTER TABLE nodes ADD COLUMN parent_lid INTEGER;
+UPDATE nodes SET parent_lid = (SELECT p.lid FROM nodes p WHERE p.uid = nodes.parent_uid);
+CREATE INDEX idx_nodes_parent_lid ON nodes(parent_lid);
+";
+
+/// Schema v41: a node made on this machine goes by `local~<lid>` until it
+/// lands, a function of its row, where it used to get a `local~<ms>-<n>`
+/// placeholder. Every placeholder still stored is rewritten to its row's
+/// stand-in: the row itself and its `node_json`, its children, the ops on it
+/// or into it, and its pins. A placeholder op with no row keeps its uid and
+/// drains as before.
+const MIGRATION_V41: &str = "
+CREATE TEMP TABLE local_v41 AS
+  SELECT uid AS old, 'local~' || lid AS new, lid FROM nodes
+   WHERE uid LIKE 'local~%' AND uid <> 'local~' || lid;
+UPDATE pending_op SET uid = (SELECT new FROM local_v41 WHERE old = pending_op.uid)
+ WHERE uid IN (SELECT old FROM local_v41);
+UPDATE pending_op SET parent_uid = (SELECT new FROM local_v41 WHERE old = pending_op.parent_uid)
+ WHERE parent_uid IN (SELECT old FROM local_v41);
+UPDATE pending_op
+   SET meta_json = json_set(meta_json, '$.uid',
+         (SELECT new FROM local_v41 WHERE old = json_extract(pending_op.meta_json, '$.uid')))
+ WHERE json_valid(meta_json)
+   AND json_extract(meta_json, '$.uid') IN (SELECT old FROM local_v41);
+UPDATE pending_op
+   SET meta_json = json_set(meta_json, '$.original_parent_uid',
+         (SELECT new FROM local_v41
+           WHERE old = json_extract(pending_op.meta_json, '$.original_parent_uid')))
+ WHERE json_valid(meta_json)
+   AND json_extract(meta_json, '$.original_parent_uid') IN (SELECT old FROM local_v41);
+UPDATE pins SET uid = (SELECT new FROM local_v41 WHERE old = pins.uid)
+ WHERE uid IN (SELECT old FROM local_v41);
+UPDATE nodes
+   SET node_json = json_set(node_json, '$.parent_uid.link_id',
+         (SELECT CAST(lid AS TEXT) FROM local_v41 WHERE old = nodes.parent_uid))
+ WHERE parent_uid IN (SELECT old FROM local_v41)
+   AND json_valid(node_json)
+   AND json_extract(node_json, '$.parent_uid.volume_id') = 'local';
+UPDATE nodes SET parent_uid = (SELECT new FROM local_v41 WHERE old = nodes.parent_uid)
+ WHERE parent_uid IN (SELECT old FROM local_v41);
+UPDATE nodes
+   SET node_json = json_set(node_json, '$.uid.link_id', CAST(lid AS TEXT))
+ WHERE lid IN (SELECT lid FROM local_v41)
+   AND json_valid(node_json)
+   AND json_extract(node_json, '$.uid.volume_id') = 'local';
+UPDATE nodes SET uid = 'local~' || lid WHERE lid IN (SELECT lid FROM local_v41);
+DROP TABLE local_v41;
+";
+
+/// Schema v42: the SHA-1 of each blob a queued create sent, space-separated.
+/// A create whose answer was lost may have made its file with any of them,
+/// and the op that finds that file again may run after a restart. `NULL` for
+/// an op that has sent nothing, which is every op migrated: what the daemon
+/// that wrote it sent is not known. Likewise the parent and name each attempt
+/// was sent under, as a JSON list of pairs: a rename since then moves the op
+/// but not the file Drive may have made.
+const MIGRATION_V42: &str = "
+ALTER TABLE pending_op ADD COLUMN sent_sha1 TEXT;
+ALTER TABLE pending_op ADD COLUMN sent_to TEXT;
+";
@@ -56,8 +56,9 @@ pub use local::LocalFileHit;
 pub use maintenance::{DbStats, VacuumOutcome};
 pub use nodes::{PublishedSharedRoot, SearchHit, StoredNode};
 pub use ops::{
-    AttachedBlob, FAILING_ATTEMPTS, LOCAL_VOLUME, OP_CREATE, OP_MKDIR, OP_RENAME, OP_REVISION,
-    OP_TRASH, PARK_EXPIRY_MS, PARK_UNTIL, PendingCounts, PendingOp, RenameMeta, op_supersedes,
+    AttachedBlob, CreateLanding, CreateRetired, FAILING_ATTEMPTS, LOCAL_VOLUME, OP_CREATE,
+    OP_MKDIR, OP_RENAME, OP_REVISION, OP_TRASH, PARK_EXPIRY_MS, PARK_UNTIL, PendingCounts,
+    PendingOp, RenameMeta, local_lid, local_uid, op_supersedes,
 };
 pub use photos::{StoredPhoto, StoredPlace, THUMB_HAVE, THUMB_NONE, THUMB_UNKNOWN, TimelineRow};
 pub use pins::PinRow;
@@ -3,9 +3,11 @@

 use std::collections::HashSet;

+use rusqlite::types::Value;
 use rusqlite::{OptionalExtension, Transaction, params};

 use super::Db;
+use super::ops::{OP_CREATE, OP_MKDIR, OP_RENAME, local_lid, local_uid, wake_ops_waiting_for_tx};
 use crate::{Access, Result};
 use proton_drive_rs::proton_sdk::ids::{LinkId, NodeUid, VolumeId};
 use proton_drive_rs::{Node, NodeKind};
@@ -17,6 +19,8 @@ use super::utils::{
 pub struct StoredNode {
    pub node: Node,
    pub listed: bool,
+    /// The row's local id ([`Db::lid_of`]).
+    pub lid: i64,
 }

 /// One full-text search match: the stored [`Node`] plus its mountpoint-relative
@@ -62,12 +66,13 @@ impl Db {
    /// snapshot while offline, including after a live event expired its TTL.
    pub fn visible_children(&self, parent: &NodeUid) -> Result<Vec<Node>> {
        let conn = self.read();
-        let mut stmt = conn.prepare(
-            "SELECT node_json FROM nodes
-              WHERE parent_uid = ?1 AND trashed = 0 AND node_json IS NOT NULL
-              ORDER BY name, uid",
-        )?;
-        let rows = stmt.query_map([parent.to_string()], |row| row.get::<_, String>(0))?;
+        let (key, parent) = parent_key(&conn, &parent.to_string())?;
+        let mut stmt = conn.prepare(&format!(
+            "SELECT {NODE_NOW} FROM nodes n LEFT JOIN nodes p ON p.lid = n.parent_lid
+              WHERE n.{key} = ?1 AND n.trashed = 0 AND n.node_json IS NOT NULL
+              ORDER BY n.name, n.uid"
+        ))?;
+        let rows = stmt.query_map([parent], |row| row.get::<_, String>(0))?;
        let mut nodes = Vec::new();
        for row in rows {
            nodes.push(serde_json::from_str(&row?)?);
@@ -264,10 +269,25 @@ impl Db {
    /// resolve its shared-tree access. Removing the op first could resurrect
    /// that row after a crash; removing the row first could strand a now
    /// unauthorizable op. One transaction closes both windows.
-    pub fn complete_trash_op(&self, op_id: i64, uid: &NodeUid) -> Result<()> {
+    ///
+    /// An op that found the name still held by this trash failed with a
+    /// backoff, and the name is free now. It is made due at once
+    /// ([`Db::wake_ops_waiting_for`]).
+    ///
+    /// Returns the staged blob of the create the trash withdrew, if it kept
+    /// one, for the caller to discard.
+    pub fn complete_trash_op(&self, op_id: i64, uid: &NodeUid) -> Result<Option<String>> {
        let uid = uid.to_string();
        let mut conn = self.conn.lock();
        let tx = conn.transaction()?;
+        let (name, blob): (Option<String>, Option<String>) = tx
+            .query_row(
+                "SELECT name, blob_path FROM pending_op WHERE id = ?1",
+                params![op_id],
+                |row| Ok((row.get(0)?, row.get(1)?)),
+            )
+            .optional()?
+            .unwrap_or_default();
        let rowid: Option<i64> = tx
            .query_row(
                "SELECT rowid FROM nodes WHERE uid = ?1",
@@ -280,17 +300,23 @@ impl Db {
            tx.execute("DELETE FROM nodes_fts WHERE rowid = ?1", params![rowid])?;
        }
        tx.execute("DELETE FROM pending_op WHERE id = ?1", params![op_id])?;
+        if let Some(name) = name {
+            wake_ops_waiting_for_tx(&tx, &name)?;
+        }
        tx.commit()?;
-        Ok(())
+        Ok(blob)
    }

    /// Check if a folder node has any non-trashed children in the database.
    pub fn has_children(&self, parent_uid: &NodeUid) -> Result<bool> {
-        let uid_str = parent_uid.to_string();
        let conn = self.read();
+        let (key, parent) = parent_key(&conn, &parent_uid.to_string())?;
        let count: i64 = conn.query_row(
-            "SELECT COUNT(*) FROM nodes WHERE parent_uid = ?1 AND trashed = 0",
-            params![uid_str],
+            &format!(
+                "SELECT COUNT(*) FROM nodes
+                 WHERE {key} = ?1 AND trashed = 0 AND node_json IS NOT NULL"
+            ),
+            params![parent],
            |row| row.get(0),
        )?;
        Ok(count > 0)
@@ -305,9 +331,11 @@ impl Db {
    pub fn node_path(&self, uid: &str) -> Result<Option<String>> {
        let conn = self.read();
        let exists: Option<i64> = conn
-            .query_row("SELECT 1 FROM nodes WHERE uid = ?1", params![uid], |r| {
-                r.get(0)
-            })
+            .query_row(
+                "SELECT 1 FROM nodes WHERE uid = ?1 AND node_json IS NOT NULL",
+                params![uid],
+                |r| r.get(0),
+            )
            .optional()?;
        if exists.is_none() {
            return Ok(None);
@@ -325,11 +353,11 @@ impl Db {
    pub fn path_relative_to(&self, ancestor_uid: &str, uid: &str) -> Result<Option<String>> {
        let conn = self.read();
        let mut stmt = conn.prepare(
-            "WITH RECURSIVE anc(uid, parent_uid, name, depth) AS (
-               SELECT uid, parent_uid, name, 0 FROM nodes WHERE uid = ?1
+            "WITH RECURSIVE anc(uid, parent_lid, name, depth) AS (
+               SELECT uid, parent_lid, name, 0 FROM nodes WHERE uid = ?1
               UNION ALL
-               SELECT n.uid, n.parent_uid, n.name, anc.depth + 1
-               FROM nodes n JOIN anc ON n.uid = anc.parent_uid
+               SELECT n.uid, n.parent_lid, n.name, anc.depth + 1
+               FROM nodes n JOIN anc ON n.lid = anc.parent_lid
               WHERE anc.depth < 1024
             )
             SELECT uid, name FROM anc ORDER BY depth",
@@ -378,12 +406,13 @@ impl Db {
        let conn = self.read();
        let rows: Vec<HitRow> = if query.chars().count() < TRIGRAM_MIN {
            let pat = format!("%{}%", like_escape(query));
-            let mut stmt = conn.prepare(
-                "SELECT node_json, uid, path FROM nodes
-                 WHERE name LIKE ?1 ESCAPE '\\' AND trashed = 0 AND node_json IS NOT NULL
-                   AND (?3 IS NULL OR path IS NULL OR path LIKE ?3 ESCAPE '\\')
-                 ORDER BY name LIMIT ?2",
-            )?;
+            let mut stmt = conn.prepare(&format!(
+                "SELECT {NODE_NOW}, n.uid, n.path
+                 FROM nodes n LEFT JOIN nodes p ON p.lid = n.parent_lid
+                 WHERE n.name LIKE ?1 ESCAPE '\\' AND n.trashed = 0 AND n.node_json IS NOT NULL
+                   AND (?3 IS NULL OR n.path IS NULL OR n.path LIKE ?3 ESCAPE '\\')
+                 ORDER BY n.name LIMIT ?2"
+            ))?;
            collect_hits(stmt.query_map(params![pat, limit as i64, scope_pat], hit_row)?)?
        } else {
            // Escape double quotes and quote each term, then combine with AND so
@@ -393,13 +422,14 @@ impl Db {
                .map(|word| format!("\"{}\"", word.replace('"', "\"\"")))
                .collect::<Vec<_>>()
                .join(" AND ");
-            let mut stmt = conn.prepare(
-                "SELECT n.node_json, n.uid, n.path
+            let mut stmt = conn.prepare(&format!(
+                "SELECT {NODE_NOW}, n.uid, n.path
                 FROM nodes_fts f JOIN nodes n ON n.rowid = f.rowid
+                 LEFT JOIN nodes p ON p.lid = n.parent_lid
                 WHERE f.name MATCH ?1 AND n.trashed = 0 AND n.node_json IS NOT NULL
                   AND (?3 IS NULL OR n.path IS NULL OR n.path LIKE ?3 ESCAPE '\\')
-                 ORDER BY f.rank LIMIT ?2",
-            )?;
+                 ORDER BY f.rank LIMIT ?2"
+            ))?;
            collect_hits(stmt.query_map(params![phrase, limit as i64, scope_pat], hit_row)?)?
        };

@@ -436,20 +466,22 @@ impl Db {
        let lane_limit = limit.div_ceil(2);
        let mut rows: Vec<HitRow> = if terms.is_empty() {
            let pat = format!("%{}%", like_escape(query));
-            let mut stmt = conn.prepare(
-                "SELECT node_json, uid, path FROM nodes
-                 WHERE name LIKE ?1 ESCAPE '\\' AND trashed = 0 AND node_json IS NOT NULL
-                 ORDER BY name LIMIT ?2",
-            )?;
+            let mut stmt = conn.prepare(&format!(
+                "SELECT {NODE_NOW}, n.uid, n.path
+                 FROM nodes n LEFT JOIN nodes p ON p.lid = n.parent_lid
+                 WHERE n.name LIKE ?1 ESCAPE '\\' AND n.trashed = 0 AND n.node_json IS NOT NULL
+                 ORDER BY n.name LIMIT ?2"
+            ))?;
            collect_hits(stmt.query_map(params![pat, limit as i64], hit_row)?)?
        } else {
            let expression = terms.join(" OR ");
-            let mut stmt = conn.prepare(
-                "SELECT n.node_json, n.uid, n.path
+            let mut stmt = conn.prepare(&format!(
+                "SELECT {NODE_NOW}, n.uid, n.path
                   FROM nodes_fts f JOIN nodes n ON n.rowid = f.rowid
+                   LEFT JOIN nodes p ON p.lid = n.parent_lid
                  WHERE nodes_fts MATCH ?1 AND n.trashed = 0 AND n.node_json IS NOT NULL
-                  ORDER BY f.rank LIMIT ?2",
-            )?;
+                  ORDER BY f.rank LIMIT ?2"
+            ))?;
            collect_hits(stmt.query_map(params![expression, lane_limit as i64], hit_row)?)?
        };
        // Trigram rank does not know that a name *starts* with the query, and a
@@ -459,12 +491,13 @@ impl Db {
        if !terms.is_empty()
            && let Some(first) = query.chars().next()
        {
-            let mut stmt = conn.prepare(
-                "SELECT node_json, uid, path FROM nodes
-                 WHERE name COLLATE NOCASE LIKE ?1 ESCAPE '\\'
-                   AND trashed = 0 AND node_json IS NOT NULL
-                 ORDER BY name COLLATE NOCASE LIMIT ?2",
-            )?;
+            let mut stmt = conn.prepare(&format!(
+                "SELECT {NODE_NOW}, n.uid, n.path
+                 FROM nodes n LEFT JOIN nodes p ON p.lid = n.parent_lid
+                 WHERE n.name COLLATE NOCASE LIKE ?1 ESCAPE '\\'
+                   AND n.trashed = 0 AND n.node_json IS NOT NULL
+                 ORDER BY n.name COLLATE NOCASE LIMIT ?2"
+            ))?;
            let mut extra = Vec::new();
            for pattern in [
                format!("{}%", like_escape(query)),
@@ -500,40 +533,50 @@ impl Db {
    /// re-enumerates from the remote on next access.
    pub fn set_listed(&self, uid: &NodeUid, listed: bool) -> Result<()> {
        let conn = self.conn.lock();
+        let (key, uid) = row_key(&uid.to_string());
        conn.execute(
-            "UPDATE nodes SET listed = ?2 WHERE uid = ?1",
-            params![uid.to_string(), listed as i64],
+            &format!("UPDATE nodes SET listed = ?2 WHERE {key} = ?1"),
+            params![uid, listed as i64],
        )?;
        Ok(())
    }

    /// Load every persisted node for cold-start hydration of the `State` maps.
+    ///
+    /// Each node names its parent as the parent's row has it now, found by
+    /// local id: a folder that landed has its new uid there, while the node
+    /// stored below it may still hold the placeholder.
    pub fn load_all(&self) -> Result<Vec<StoredNode>> {
        let conn = self.read();
-        let mut stmt =
-            conn.prepare("SELECT node_json, listed FROM nodes WHERE node_json IS NOT NULL")?;
+        let mut stmt = conn.prepare(&format!(
+            "SELECT {NODE_NOW}, n.listed, n.lid
+             FROM nodes n LEFT JOIN nodes p ON p.lid = n.parent_lid
+             WHERE n.node_json IS NOT NULL"
+        ))?;
        let rows = stmt.query_map([], |row| {
            let json: String = row.get(0)?;
            let listed: i64 = row.get(1)?;
-            Ok((json, listed != 0))
+            Ok((json, listed != 0, row.get(2)?))
        })?;
        let mut out = Vec::new();
        for row in rows {
-            let (json, listed) = row?;
+            let (json, listed, lid) = row?;
            let node: Node = serde_json::from_str(&json)?;
-            out.push(StoredNode { node, listed });
+            out.push(StoredNode { node, listed, lid });
        }
        Ok(out)
    }

    /// Load one persisted node back by uid. Used to recover the My Files root
-    /// when the API is unreachable, so the mount can still serve the cached tree
-    /// (offline.md Phase 1).
+    /// when the API is unreachable, so the mount can still serve the cached tree.
    pub fn node_by_uid(&self, uid: &str) -> Result<Option<Node>> {
        let conn = self.read();
        let json: Option<String> = conn
            .query_row(
-                "SELECT node_json FROM nodes WHERE uid = ?1 AND node_json IS NOT NULL",
+                &format!(
+                    "SELECT {NODE_NOW} FROM nodes n LEFT JOIN nodes p ON p.lid = n.parent_lid
+                     WHERE n.uid = ?1 AND n.node_json IS NOT NULL"
+                ),
                params![uid],
                |r| r.get(0),
            )
@@ -544,31 +587,178 @@ impl Db {
        }
    }

+    /// The uid of the node with local id `lid`: `None` when it has no row, or
+    /// is not on Drive yet.
+    pub fn uid_of_lid(&self, lid: i64) -> Result<Option<String>> {
+        let conn = self.read();
+        Ok(conn
+            .query_row("SELECT uid FROM nodes WHERE lid = ?1", params![lid], |r| {
+                r.get(0)
+            })
+            .optional()?
+            .flatten())
+    }
+
+    /// The local id of the node stored under `uid`, or `None` when it has no
+    /// row. It stays the same for as long as the row exists, including when a
+    /// create lands and the row takes the uid Drive gave it: a node made on
+    /// this machine is found by its stand-in ([`local_uid`]) before and after.
+    pub fn lid_of(&self, uid: &str) -> Result<Option<i64>> {
+        node_lid(&self.read(), uid)
+    }
+
+    /// The local id of each node, in order, giving a row to each that has none.
+    ///
+    /// A new row is only a stub: it has no `node_json`, so no listing or search
+    /// returns it until the node is upserted, which the caller still owes. That
+    /// keeps this cheap enough to call with the inode lock held, which is
+    /// where an inode number is first needed.
+    pub fn lids_for(&self, nodes: &[&Node]) -> Result<Vec<i64>> {
+        let mut conn = self.conn.lock();
+        let tx = conn.transaction()?;
+        let mut lids = Vec::with_capacity(nodes.len());
+        {
+            let mut known = tx.prepare_cached("SELECT lid FROM nodes WHERE uid = ?1")?;
+            let mut stub = tx.prepare_cached(
+                "INSERT INTO nodes (uid, parent_uid, name, is_dir, mtime, trashed, parent_lid)
+                 VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7)",
+            )?;
+            for node in nodes {
+                let uid = node.uid.to_string();
+                let lid = match known.query_row(params![uid], |r| r.get(0)).optional()? {
+                    Some(lid) => lid,
+                    None => {
+                        let parent = node.parent_uid.as_ref().map(ToString::to_string);
+                        let parent_lid = match &parent {
+                            Some(parent) => node_lid(&tx, parent)?,
+                            None => None,
+                        };
+                        stub.execute(params![
+                            uid,
+                            parent,
+                            node.name,
+                            node.is_folder() as i64,
+                            node.modification_time,
+                            node.trashed as i64,
+                            parent_lid,
+                        ])?;
+                        let lid = tx.last_insert_rowid();
+                        adopt_children_tx(&tx, &uid, lid)?;
+                        lid
+                    }
+                };
+                lids.push(lid);
+            }
+        }
+        tx.commit()?;
+        Ok(lids)
+    }
+
+    /// Give a node being made on this machine its row under `parent_uid`, and
+    /// return its local id. The row goes by [`local_uid`] of that id until
+    /// the node lands.
+    ///
+    /// Like [`Db::lids_for`], only a stub: the caller upserts the node.
+    pub fn add_local_row(
+        &self,
+        parent_uid: &str,
+        name: &str,
+        is_dir: bool,
+        mtime: i64,
+    ) -> Result<i64> {
+        let mut conn = self.conn.lock();
+        let tx = conn.transaction()?;
+        tx.execute(
+            "INSERT INTO nodes (uid, parent_uid, name, is_dir, mtime, trashed, parent_lid)
+             VALUES (NULL, ?1, ?2, ?3, ?4, 0,
+                     COALESCE(?5, (SELECT lid FROM nodes WHERE uid = ?1)))",
+            params![
+                parent_uid,
+                name,
+                is_dir as i64,
+                mtime,
+                local_lid(parent_uid)
+            ],
+        )?;
+        let lid = tx.last_insert_rowid();
+        tx.execute(
+            "UPDATE nodes SET uid = ?2 WHERE lid = ?1",
+            params![lid, local_uid(lid)],
+        )?;
+        tx.commit()?;
+        Ok(lid)
+    }
+
    /// Read the persisted incremental-sync cursor (a `DriveEventId`), if any.
    /// The daemon resumes from this on restart instead of reseeding to the
    /// server head, so changes made while unmounted are still applied (P2).
    pub fn children_if_listed(&self, parent: &NodeUid) -> Result<Option<Vec<Node>>> {
        let conn = self.read();
+        let (key, folder) = row_key(&parent.to_string());
        let listed: Option<i64> = conn
            .query_row(
-                "SELECT listed FROM nodes WHERE uid = ?1",
-                params![parent.to_string()],
+                &format!("SELECT listed FROM nodes WHERE {key} = ?1"),
+                params![folder],
                |r| r.get(0),
            )
            .optional()?;
        if listed != Some(1) {
            return Ok(None);
        }
-        let mut stmt = conn.prepare(
-            "SELECT node_json FROM nodes
-             WHERE parent_uid = ?1 AND node_json IS NOT NULL AND trashed = 0",
-        )?;
-        let rows = stmt.query_map(params![parent.to_string()], |r| r.get::<_, String>(0))?;
+        drop(conn);
+        self.known_children(parent).map(Some)
+    }
+
+    /// The children the DB knows under `parent`, whether or not the folder's
+    /// listing is still marked complete. Only for when nothing better can be
+    /// had: a listing dropped as stale may miss or keep a child.
+    pub fn known_children(&self, parent: &NodeUid) -> Result<Vec<Node>> {
+        let conn = self.read();
+        let (key, parent) = parent_key(&conn, &parent.to_string())?;
+        let mut stmt = conn.prepare(&format!(
+            "SELECT {NODE_NOW} FROM nodes n LEFT JOIN nodes p ON p.lid = n.parent_lid
+             WHERE n.{key} = ?1 AND n.node_json IS NOT NULL AND n.trashed = 0"
+        ))?;
+        let rows = stmt.query_map(params![parent], |r| r.get::<_, String>(0))?;
        let mut out = Vec::new();
        for json in rows {
            out.push(serde_json::from_str(&json?)?);
        }
-        Ok(Some(out))
+        Ok(out)
+    }
+
+    /// What a queued change does to `parent`'s listing, which Drive does not
+    /// show until it lands: the children made or moved in by a queued create,
+    /// mkdir or rename, as the DB holds them, and the nodes a queued rename
+    /// moves elsewhere.
+    ///
+    /// A listing read from Drive is laid over with these, or a folder listed
+    /// while a create in it is queued, after a restart say, loses the file
+    /// until the create lands (`docs/BUGS.md` B132).
+    pub fn queued_children(&self, parent: &NodeUid) -> Result<(Vec<Node>, HashSet<String>)> {
+        let conn = self.read();
+        let (key, parent) = parent_key(&conn, &parent.to_string())?;
+        let mut stmt = conn.prepare(&format!(
+            "SELECT {NODE_NOW} FROM nodes n LEFT JOIN nodes p ON p.lid = n.parent_lid
+             WHERE n.{key} = ?1 AND n.node_json IS NOT NULL AND n.trashed = 0
+               AND EXISTS (SELECT 1 FROM pending_op o
+                           WHERE (o.lid = n.lid OR o.uid = n.uid) AND o.kind IN (?2, ?3, ?4))"
+        ))?;
+        let rows = stmt.query_map(params![parent, OP_CREATE, OP_MKDIR, OP_RENAME], |r| {
+            r.get::<_, String>(0)
+        })?;
+        let mut here = Vec::new();
+        for json in rows {
+            here.push(serde_json::from_str(&json?)?);
+        }
+        let mut stmt = conn.prepare(&format!(
+            "SELECT DISTINCT n.uid FROM pending_op p JOIN nodes n ON n.lid = p.lid OR n.uid = p.uid
+             WHERE p.kind = ?2 AND n.{key} IS NOT ?1"
+        ))?;
+        let gone = stmt
+            .query_map(params![parent, OP_RENAME], |r| r.get::<_, String>(0))?
+            .collect::<std::result::Result<HashSet<_>, _>>()?;
+        Ok((here, gone))
    }

    // --- Content-cache LRU index (P4) -------------------------------------
@@ -590,9 +780,157 @@ struct PriorRow {
    trashed: bool,
 }

+/// [`Db::lid_of`] on `conn`, which may be a transaction.
+pub(super) fn node_lid(conn: &rusqlite::Connection, uid: &str) -> Result<Option<i64>> {
+    let row = match local_lid(uid) {
+        Some(lid) => conn.query_row("SELECT lid FROM nodes WHERE lid = ?1", params![lid], |r| {
+            r.get(0)
+        }),
+        None => conn.query_row("SELECT lid FROM nodes WHERE uid = ?1", params![uid], |r| {
+            r.get(0)
+        }),
+    };
+    Ok(row.optional()?)
+}
+
+/// The column and value that find `uid`'s own row. A stand-in is found by its
+/// local id: a create that lands gives the row the uid Drive made before the
+/// tree has it, and the tree asks by the stand-in until then (`docs/BUGS.md`
+/// B177).
+fn row_key(uid: &str) -> (&'static str, Value) {
+    match local_lid(uid) {
+        Some(lid) => ("lid", Value::Integer(lid)),
+        None => ("uid", Value::Text(uid.to_owned())),
+    }
+}
+
+/// The column and value a row names `parent` by: its local id when it has a
+/// row, which the children keep when it lands, or its uid when it has none,
+/// as a device folder's root does.
+fn parent_key(conn: &rusqlite::Connection, parent: &str) -> Result<(&'static str, Value)> {
+    Ok(match node_lid(conn, parent)? {
+        Some(lid) => ("parent_lid", Value::Integer(lid)),
+        None => ("parent_uid", Value::Text(parent.to_owned())),
+    })
+}
+
+/// `n.node_json` naming its parent as the parent's row `p`, joined by
+/// `n.parent_lid`, has it now. A folder that lands takes its real uid in its
+/// own row only, so a node stored below it still names the stand-in.
+const NODE_NOW: &str = "CASE WHEN p.uid IS NULL OR p.uid = n.parent_uid THEN n.node_json
+     ELSE json_set(n.node_json, '$.parent_uid', json_object(
+            'volume_id', substr(p.uid, 1, instr(p.uid, '~') - 1),
+            'link_id', substr(p.uid, instr(p.uid, '~') + 1))) END";
+
+/// Hand a drained placeholder's row to the real uid it landed as.
+///
+/// Nothing else is rewritten. The rows below it and the ops made inside it
+/// name it by its local id, which stays; what reads them for a uid takes the
+/// one the row has now ([`NODE_NOW`], `PARENT_NOW` in `ops.rs`).
+///
+/// Dropping the placeholder row and waiting for the server's copy of the real
+/// node left a window with no row for either uid. A queued child drained in
+/// that window found no authority for its parent, re-read it over the network
+/// and was deferred five seconds behind a folder that had just landed
+/// (`docs/BUGS.md` B120). The placeholder's own node, readdressed, stands in
+/// until the server's copy is upserted over it. A row the real uid already
+/// has is newer than the placeholder, so its node is kept, under the
+/// placeholder's `lid`: the node was known by that one first.
+pub(super) fn adopt_placeholder_row_tx(
+    tx: &Transaction<'_>,
+    local: &str,
+    real: &str,
+) -> Result<()> {
+    // A folder pinned before it landed stays pinned: the pin keyed by the
+    // placeholder was dropped with it (`docs/BUGS.md` B148).
+    tx.execute(
+        "UPDATE OR IGNORE pins SET uid = ?2 WHERE uid = ?1",
+        params![local, real],
+    )?;
+    tx.execute("DELETE FROM pins WHERE uid = ?1", params![local])?;
+    let row: Option<(i64, Option<String>)> = tx
+        .query_row(
+            "SELECT lid, node_json FROM nodes WHERE uid = ?1",
+            params![local],
+            |row| Ok((row.get(0)?, row.get(1)?)),
+        )
+        .optional()?;
+    // Ops queued before schema 39 have no `parent_lid`, nor do ops made
+    // under a placeholder that never had a row.
+    tx.execute(
+        "UPDATE pending_op SET parent_uid = ?2 WHERE parent_lid IS NULL AND parent_uid = ?1",
+        params![local, real],
+    )?;
+    let Some((lid, json)) = row else {
+        return Ok(());
+    };
+    let known: Option<(i64, Option<String>)> = tx
+        .query_row(
+            "SELECT lid, node_json FROM nodes WHERE uid = ?1",
+            params![real],
+            |row| Ok((row.get(0)?, row.get(1)?)),
+        )
+        .optional()?;
+    if let Some((known_lid, _)) = known {
+        // Ops queued against the row Drive listed now name the landing one.
+        tx.execute(
+            "UPDATE pending_op SET lid = ?2 WHERE lid = ?1",
+            params![known_lid, lid],
+        )?;
+        tx.execute(
+            "UPDATE pending_op SET parent_lid = ?2 WHERE parent_lid = ?1",
+            params![known_lid, lid],
+        )?;
+        tx.execute(
+            "UPDATE nodes SET parent_lid = ?2 WHERE parent_lid = ?1",
+            params![known_lid, lid],
+        )?;
+        tx.execute("DELETE FROM nodes WHERE lid = ?1", params![known_lid])?;
+        tx.execute("DELETE FROM nodes_fts WHERE rowid = ?1", params![known_lid])?;
+    }
+    tx.execute(
+        "UPDATE nodes SET uid = ?2 WHERE lid = ?1",
+        params![lid, real],
+    )?;
+    let json = known.and_then(|(_, known_json)| known_json).or(json);
+    let (Some(json), Some(real)) = (json, parse_node_uid(real)) else {
+        return Ok(());
+    };
+    let mut node: Node = serde_json::from_str(&json)?;
+    node.uid = real;
+    upsert_node_tx(tx, &node)
+}
+
+/// Link the rows that name `uid` as their parent to its new row `lid`: they
+/// were stored before it, or under a row of the same uid since dropped.
+fn adopt_children_tx(tx: &Transaction<'_>, uid: &str, lid: i64) -> Result<()> {
+    tx.execute(
+        "UPDATE nodes SET parent_lid = ?2 WHERE parent_uid = ?1 AND parent_lid IS NOT ?2",
+        params![uid, lid],
+    )?;
+    Ok(())
+}
+
 fn upsert_node_tx(tx: &Transaction<'_>, node: &Node) -> Result<()> {
-    let json = serde_json::to_string(node)?;
    let uid = node.uid.to_string();
+    // A node written under its stand-in after it landed is its row, which has
+    // the uid Drive gave it by now: written under the stand-in, it would bring
+    // the placeholder row back beside it.
+    if let Some(lid) = local_lid(&uid) {
+        let landed: Option<String> = tx
+            .query_row(
+                "SELECT uid FROM nodes WHERE lid = ?1 AND uid IS NOT ?2",
+                params![lid, uid],
+                |row| row.get(0),
+            )
+            .optional()?;
+        if let Some(real) = landed.as_deref().and_then(parse_node_uid) {
+            let mut node = node.clone();
+            node.uid = real;
+            return upsert_node_tx(tx, &node);
+        }
+    }
+    let json = serde_json::to_string(node)?;
    let parent_uid = node.parent_uid.as_ref().map(|u| u.to_string());

    let prior: Option<PriorRow> = tx
@@ -614,26 +952,34 @@ fn upsert_node_tx(tx: &Transaction<'_>, node: &Node) -> Result<()> {
    // where resolving it from scratch is a recursive walk to the root. A node
    // whose parent is not cached (a device folder's root lives in `device`, never
    // in `nodes`) starts a path of its own, which is what the walk did too.
-    let path = match &parent_uid {
-        None => String::new(),
+    let (parent_lid, path) = match &parent_uid {
+        None => (None, String::new()),
        Some(parent) => {
-            let parent_path: Option<Option<String>> = tx
-                .query_row(
-                    "SELECT path FROM nodes WHERE uid = ?1",
-                    params![parent],
-                    |row| row.get(0),
-                )
-                .optional()?;
-            join_path(parent_path.flatten().as_deref().unwrap_or(""), &node.name)
+            let parent_row: Option<(i64, Option<String>)> = match node_lid(tx, parent)? {
+                Some(lid) => tx
+                    .query_row(
+                        "SELECT lid, path FROM nodes WHERE lid = ?1",
+                        params![lid],
+                        |row| Ok((row.get(0)?, row.get(1)?)),
+                    )
+                    .optional()?,
+                None => None,
+            };
+            let (lid, parent_path) = parent_row.unzip();
+            (
+                lid,
+                join_path(parent_path.flatten().as_deref().unwrap_or(""), &node.name),
+            )
        }
    };

    tx.execute(
        "INSERT INTO nodes
-           (uid, parent_uid, name, is_dir, size, mtime, trashed, node_json, path)
-         VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9)
+           (uid, parent_uid, name, is_dir, size, mtime, trashed, node_json, path, parent_lid)
+         VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10)
         ON CONFLICT(uid) DO UPDATE SET
           parent_uid = excluded.parent_uid,
+           parent_lid = excluded.parent_lid,
           name       = excluded.name,
           is_dir     = excluded.is_dir,
           size       = excluded.size,
@@ -651,6 +997,7 @@ fn upsert_node_tx(tx: &Transaction<'_>, node: &Node) -> Result<()> {
            node.trashed as i64,
            json,
            path,
+            parent_lid,
        ],
    )?;
    let rowid: i64 = tx.query_row(
@@ -658,6 +1005,9 @@ fn upsert_node_tx(tx: &Transaction<'_>, node: &Node) -> Result<()> {
        params![uid],
        |row| row.get(0),
    )?;
+    if prior.is_none() {
+        adopt_children_tx(tx, &uid, rowid)?;
+    }

    // FTS5 has no UPSERT, so the node's own row is always replaced.
    let indexable = node_is_indexable_tx(tx, &uid)?;
@@ -680,7 +1030,7 @@ fn upsert_node_tx(tx: &Transaction<'_>, node: &Node) -> Result<()> {
            || prior.trashed != node.trashed
    });
    if node.is_folder() && subtree_moved {
-        reindex_subtree_tx(tx, &uid, &path, indexable)?;
+        reindex_subtree_tx(tx, rowid, &path, indexable)?;
    }
    Ok(())
 }
@@ -701,22 +1051,22 @@ fn upsert_node_tx(tx: &Transaction<'_>, node: &Node) -> Result<()> {
 /// this deep.
 fn reindex_subtree_tx(
    tx: &Transaction<'_>,
-    folder: &str,
+    folder: i64,
    folder_path: &str,
    folder_indexable: bool,
 ) -> Result<()> {
    let descendants: Vec<(i64, String, bool)> = {
        let mut stmt = tx.prepare(
-            "WITH RECURSIVE sub(rowid, uid, name, path, blocked, depth) AS (
-               SELECT n.rowid, n.uid, n.name,
+            "WITH RECURSIVE sub(rowid, name, path, blocked, depth) AS (
+               SELECT n.rowid, n.name,
                      CASE WHEN ?2 = '' THEN n.name ELSE ?2 || '/' || n.name END,
                      n.trashed, 0
-                 FROM nodes n WHERE n.parent_uid = ?1
+                 FROM nodes n WHERE n.parent_lid = ?1
               UNION ALL
-               SELECT n.rowid, n.uid, n.name,
+               SELECT n.rowid, n.name,
                      sub.path || '/' || n.name,
                      MAX(sub.blocked, n.trashed), sub.depth + 1
-                 FROM nodes n JOIN sub ON n.parent_uid = sub.uid
+                 FROM nodes n JOIN sub ON n.parent_lid = sub.rowid
                WHERE sub.depth < 256
             )
             SELECT rowid, path, blocked FROM sub",
@@ -741,8 +1091,10 @@ fn reindex_subtree_tx(
    let mut set_path = tx.prepare("UPDATE nodes SET path = ?2 WHERE rowid = ?1")?;
    let mut unindex = tx.prepare("DELETE FROM nodes_fts WHERE rowid = ?1")?;
    let mut index = tx.prepare(
+        // Not a stub row (`Db::lids_for`): it is indexed when its node is
+        // written.
        "INSERT INTO nodes_fts (rowid, name, path)
-         SELECT rowid, name, ?2 FROM nodes WHERE rowid = ?1",
+         SELECT rowid, name, ?2 FROM nodes WHERE rowid = ?1 AND node_json IS NOT NULL",
    )?;
    for (rowid, path, blocked) in descendants {
        set_path.execute(params![rowid, path])?;
@@ -755,7 +1107,8 @@ fn reindex_subtree_tx(
 }

 fn direct_child_uids_tx(tx: &Transaction<'_>, parent: &str) -> Result<Vec<String>> {
-    let mut stmt = tx.prepare("SELECT uid FROM nodes WHERE parent_uid = ?1")?;
+    let (key, parent) = parent_key(tx, parent)?;
+    let mut stmt = tx.prepare(&format!("SELECT uid FROM nodes WHERE {key} = ?1"))?;
    let rows = stmt.query_map([parent], |row| row.get::<_, String>(0))?;
    let mut uids = Vec::new();
    for row in rows {
@@ -780,14 +1133,14 @@ fn direct_child_uids_tx(tx: &Transaction<'_>, parent: &str) -> Result<Vec<String
 /// ends at one whose parent is a row we have already visited.
 fn node_is_indexable_tx(tx: &Transaction<'_>, uid: &str) -> Result<bool> {
    let indexable: i64 = tx.query_row(
-        "WITH RECURSIVE ancestors(uid, parent_uid, trashed, depth, path) AS (
-           SELECT uid, parent_uid, trashed, 0, char(31) || uid || char(31)
+        "WITH RECURSIVE ancestors(lid, parent_lid, trashed, depth, path) AS (
+           SELECT lid, parent_lid, trashed, 0, ',' || lid || ','
             FROM nodes WHERE uid = ?1
           UNION ALL
-           SELECT n.uid, n.parent_uid, n.trashed, a.depth + 1,
-                  a.path || n.uid || char(31)
-             FROM ancestors a JOIN nodes n ON n.uid = a.parent_uid
-            WHERE instr(a.path, char(31) || n.uid || char(31)) = 0
+           SELECT n.lid, n.parent_lid, n.trashed, a.depth + 1,
+                  a.path || n.lid || ','
+             FROM ancestors a JOIN nodes n ON n.lid = a.parent_lid
+            WHERE instr(a.path, ',' || n.lid || ',') = 0
         )
         SELECT CASE
           WHEN COUNT(*) = 0 THEN 0
@@ -795,8 +1148,7 @@ fn node_is_indexable_tx(tx: &Transaction<'_>, uid: &str) -> Result<bool> {
           WHEN EXISTS (
             SELECT 1 FROM ancestors a
              WHERE a.depth = (SELECT MAX(depth) FROM ancestors)
-                AND a.parent_uid IS NOT NULL
-                AND EXISTS (SELECT 1 FROM nodes p WHERE p.uid = a.parent_uid)
+                AND EXISTS (SELECT 1 FROM nodes p WHERE p.lid = a.parent_lid)
           ) THEN 0
           ELSE 1
         END
@@ -814,7 +1166,7 @@ fn tombstone_subtree_tx(tx: &Transaction<'_>, root_uid: &str) -> Result<()> {
               SELECT rowid, uid, node_json FROM nodes WHERE uid = ?1
               UNION
               SELECT n.rowid, n.uid, n.node_json FROM nodes n
-                 JOIN subtree s ON n.parent_uid = s.uid
+                 JOIN subtree s ON n.parent_lid = s.rowid
             )
             SELECT rowid, uid, node_json FROM subtree",
        )?;
@@ -64,11 +64,11 @@ impl Db {
    }

    /// Whether `uid` is pinned — directly, or because a strict ancestor folder
-    /// is pinned recursively. The ancestor check walks `parent_uid` to the root
+    /// is pinned recursively. The ancestor check walks `parent_lid` to the root
    /// via a CTE; a direct pin is honoured even when the node has no `nodes` row
    /// yet (e.g. a CLI that never hydrates the node cache).
    ///
-    /// The walk is depth-capped like [`super::utils::path_of`]: a `parent_uid`
+    /// The walk is depth-capped like [`super::utils::path_of`]: a parent
    /// cycle is corrupt data the API can hand us, and `UNION ALL` over one never
    /// terminates — while holding the daemon's only SQLite connection, on a path
    /// that runs per cached read.
@@ -85,11 +85,11 @@ impl Db {
        let anc: Option<i64> = conn
            .query_row(
                &format!(
-                    "WITH RECURSIVE anc(uid, parent_uid, depth) AS (
-                       SELECT uid, parent_uid, 0 FROM nodes WHERE uid = ?1
+                    "WITH RECURSIVE anc(uid, parent_lid, depth) AS (
+                       SELECT uid, parent_lid, 0 FROM nodes WHERE uid = ?1
                       UNION ALL
-                       SELECT n.uid, n.parent_uid, anc.depth + 1
-                       FROM nodes n JOIN anc ON n.uid = anc.parent_uid
+                       SELECT n.uid, n.parent_lid, anc.depth + 1
+                       FROM nodes n JOIN anc ON n.lid = anc.parent_lid
                       WHERE anc.depth < {MAX_PATH_DEPTH}
                     )
                     SELECT 1 FROM anc a JOIN pins p ON p.uid = a.uid
@@ -109,10 +109,11 @@ impl Db {
    pub fn pinned_uids(&self) -> Result<Vec<String>> {
        let conn = self.read();
        let mut stmt = conn.prepare(
-            "WITH RECURSIVE sub(uid) AS (
-               SELECT uid FROM pins WHERE recursive = 1
+            "WITH RECURSIVE sub(uid, lid) AS (
+               SELECT p.uid, n.lid FROM pins p LEFT JOIN nodes n ON n.uid = p.uid
+                WHERE p.recursive = 1
               UNION
-               SELECT n.uid FROM nodes n JOIN sub ON n.parent_uid = sub.uid
+               SELECT n.uid, n.lid FROM nodes n JOIN sub ON n.parent_lid = sub.lid
             )
             SELECT uid FROM sub
             UNION
@@ -126,15 +127,16 @@ impl Db {
        Ok(out)
    }

-    /// Every descendant uid of `folder` (all depths), via a `parent_uid` CTE.
+    /// Every descendant uid of `folder` (all depths), via a `parent_lid` CTE.
    /// Used to evict a recursively-pinned subtree's cached blobs on unpin.
    pub fn descendants(&self, folder: &str) -> Result<Vec<String>> {
        let conn = self.read();
        let mut stmt = conn.prepare(
-            "WITH RECURSIVE sub(uid) AS (
-               SELECT uid FROM nodes WHERE parent_uid = ?1
+            "WITH RECURSIVE sub(uid, lid) AS (
+               SELECT c.uid, c.lid FROM nodes c JOIN nodes f ON c.parent_lid = f.lid
+                WHERE f.uid = ?1
               UNION
-               SELECT n.uid FROM nodes n JOIN sub ON n.parent_uid = sub.uid
+               SELECT n.uid, n.lid FROM nodes n JOIN sub ON n.parent_lid = sub.lid
             )
             SELECT uid FROM sub",
        )?;
@@ -95,11 +95,27 @@ impl Db {
    /// Resolve a persisted node's effective access through its nearest recorded
    /// share root. `None` means the node itself is not persisted, which callers
    /// must not treat as owned: stale handles need to fail closed.
+    ///
+    /// A stand-in ([`local_uid`](super::local_uid)) finds its row by local id,
+    /// so it still does once its create has landed and the row has the uid
+    /// Drive gave it. The tree learns that uid a moment later, and a rename in
+    /// between was refused (`docs/BUGS.md` B174).
    pub fn effective_node_access(&self, uid: &NodeUid) -> Result<Option<Access>> {
        let conn = self.read();
+        let key = uid.to_string();
+        let key = match super::local_lid(&key) {
+            Some(lid) => conn
+                .query_row("SELECT uid FROM nodes WHERE lid = ?1", [lid], |row| {
+                    row.get::<_, Option<String>>(0)
+                })
+                .optional()?
+                .flatten()
+                .unwrap_or(key),
+            None => key,
+        };
        let exists: bool = conn.query_row(
-            "SELECT EXISTS(SELECT 1 FROM nodes WHERE uid = ?1)",
-            [uid.to_string()],
+            "SELECT EXISTS(SELECT 1 FROM nodes WHERE uid = ?1 AND node_json IS NOT NULL)",
+            [&key],
            |row| row.get(0),
        )?;
        if !exists {
@@ -107,25 +123,26 @@ impl Db {
        }
        let value = conn
            .query_row(
-                "WITH RECURSIVE ancestors(uid, parent_uid, depth, path) AS (
-                   SELECT uid, parent_uid, 0, char(31) || uid || char(31)
+                "WITH RECURSIVE ancestors(uid, parent_uid, parent_lid, depth, path) AS (
+                   SELECT uid, parent_uid, parent_lid, 0, char(31) || uid || char(31)
                     FROM nodes WHERE uid = ?1
                   UNION ALL
-                   SELECT a.parent_uid, n.parent_uid, a.depth + 1,
-                          a.path || a.parent_uid || char(31)
+                   SELECT COALESCE(n.uid, a.parent_uid), n.parent_uid, n.parent_lid,
+                          a.depth + 1,
+                          a.path || COALESCE(n.uid, a.parent_uid) || char(31)
                     FROM ancestors a
-                     LEFT JOIN nodes n ON n.uid = a.parent_uid
+                     LEFT JOIN nodes n ON n.lid = a.parent_lid
                    WHERE a.parent_uid IS NOT NULL
                      AND instr(
                            a.path,
-                            char(31) || a.parent_uid || char(31)
+                            char(31) || COALESCE(n.uid, a.parent_uid) || char(31)
                          ) = 0
                 )
                 SELECT sa.access
                   FROM ancestors a JOIN share_access sa ON sa.root_uid = a.uid
                  ORDER BY a.depth ASC
                  LIMIT 1",
-                [uid.to_string()],
+                [&key],
                |row| row.get::<_, String>(0),
            )
            .optional()?;
@@ -25,8 +25,8 @@ pub struct StoredSyncFolder {
 }

 /// One per-file sync baseline row: what a path looked like on both sides at the
-/// last successful sync, so the next reconcile can tell which side changed
-/// (devices.md Phase 2). `remote_rev`/`remote_hash` hold the remote signature —
+/// last successful sync, so the next reconcile can tell which side changed.
+/// `remote_rev`/`remote_hash` hold the remote signature —
 /// its modification time and size as strings — since no cheap content hash is
 /// exposed; change detection is `(mtime, size)` on each side.
 #[derive(Clone, Debug, PartialEq)]
@@ -39,7 +39,7 @@ pub struct StoredSyncEntry {
    ///
    /// `local_mtime` alone cannot tell an edit that landed inside the same
    /// second as the last sync — and left the file the same length — from no
-    /// edit at all, so those never uploaded (bugs.md B25). `None` on a row
+    /// edit at all, so those never uploaded (`docs/BUGS.md` B25). `None` on a row
    /// written before schema 28, which the comparison reads as "compare whole
    /// seconds", so upgrading does not make an entire mirror look changed.
    pub local_mtime_ns: Option<i64>,
@@ -260,10 +260,92 @@ impl Db {
        Ok(())
    }

+    /// Drop the baseline rows of `rel_path` and everything under it.
+    ///
+    /// Used when a subtree leaves a mirror folder through a move on Drive: its
+    /// local copy is about to be removed, and rows left behind would read as
+    /// "deleted locally" and trash the moved nodes at their new place.
+    pub fn sync_entries_remove_subtree(&self, folder_id: i64, rel_path: &str) -> Result<()> {
+        let conn = self.conn.lock();
+        conn.execute(
+            "DELETE FROM sync_entry
+              WHERE folder_id = ?1
+                AND (rel_path = ?2 OR substr(rel_path, 1, length(?2) + 1) = ?2 || '/')",
+            params![folder_id, rel_path],
+        )?;
+        Ok(())
+    }
+
+    /// Move the baseline rows of `from_rel` and everything under it to `to_rel`
+    /// in folder `to_folder`, in one transaction.
+    ///
+    /// Used when a move on Drive took a mirror subtree along with its local
+    /// copy: the rows still describe both sides correctly, only under a new
+    /// path, so the next pass on either folder has nothing to do. The two
+    /// folders may be the same one.
+    pub fn sync_entries_move(
+        &self,
+        from_folder: i64,
+        from_rel: &str,
+        to_folder: i64,
+        to_rel: &str,
+    ) -> Result<()> {
+        let mut conn = self.conn.lock();
+        let tx = conn.transaction()?;
+        {
+            let mut select = tx.prepare(
+                "SELECT rel_path, remote_uid, local_mtime, local_size, remote_rev, remote_hash,
+                        local_mtime_ns
+                   FROM sync_entry
+                  WHERE folder_id = ?1
+                    AND (rel_path = ?2 OR substr(rel_path, 1, length(?2) + 1) = ?2 || '/')",
+            )?;
+            let rows = select
+                .query_map(params![from_folder, from_rel], |r| {
+                    Ok(StoredSyncEntry {
+                        rel_path: r.get(0)?,
+                        remote_uid: r.get(1)?,
+                        local_mtime: r.get(2)?,
+                        local_size: r.get(3)?,
+                        remote_rev: r.get(4)?,
+                        remote_hash: r.get(5)?,
+                        local_mtime_ns: r.get(6)?,
+                    })
+                })?
+                .collect::<rusqlite::Result<Vec<_>>>()?;
+            let mut delete =
+                tx.prepare("DELETE FROM sync_entry WHERE folder_id = ?1 AND rel_path = ?2")?;
+            for row in &rows {
+                delete.execute(params![from_folder, row.rel_path])?;
+            }
+            let mut insert = tx.prepare(
+                "INSERT OR REPLACE INTO sync_entry
+                   (folder_id, rel_path, remote_uid, local_mtime, local_size, remote_rev,
+                    remote_hash, local_mtime_ns)
+                 VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8)",
+            )?;
+            for row in rows {
+                let rel = format!("{to_rel}{}", &row.rel_path[from_rel.len()..]);
+                insert.execute(params![
+                    to_folder,
+                    rel,
+                    row.remote_uid,
+                    row.local_mtime,
+                    row.local_size,
+                    row.remote_rev,
+                    row.remote_hash,
+                    row.local_mtime_ns,
+                ])?;
+            }
+        }
+        tx.commit()?;
+        Ok(())
+    }
+
    /// Drop the entire baseline for a folder. Used when flipping ondemand→mirror:
    /// the local tree was evicted, so the old baseline is stale and would make the
    /// next reconcile mistake "locally deleted" for "must re-download". Clearing it
-    /// leaves an empty baseline + full remote = pure download (devices.md P3).
+    /// leaves an empty baseline + full remote = pure download.
    pub fn sync_entries_clear(&self, folder_id: i64) -> Result<()> {
        let conn = self.conn.lock();
        conn.execute(
@@ -102,5 +102,5 @@ impl Db {
        Ok(seen)
    }

-    // ---- device sync (devices.md) -----------------------------------------
+    // ---- device sync -----------------------------------------
 }
@@ -72,18 +72,18 @@ pub(super) fn path_of(conn: &Connection, uid: &str) -> Result<String> {
    }
 }

-/// Resolve a path by walking `parent_uid` to the root via a recursive CTE.
+/// Resolve a path by walking `parent_lid` to the root via a recursive CTE.
 ///
-/// A cycle in `parent_uid` is corrupt data the API can still hand us, and
+/// A cycle in the parents is corrupt data the API can still hand us, and
 /// `UNION ALL` over one never terminates — the walk is therefore depth-capped
 /// and returns the truncated path rather than hanging the caller.
 pub(super) fn walk_path_of(conn: &Connection, uid: &str) -> Result<String> {
    let mut stmt = conn.prepare(&format!(
-        "WITH RECURSIVE anc(uid, parent_uid, name, depth) AS (
-           SELECT uid, parent_uid, name, 0 FROM nodes WHERE uid = ?1
+        "WITH RECURSIVE anc(parent_lid, parent_uid, name, depth) AS (
+           SELECT parent_lid, parent_uid, name, 0 FROM nodes WHERE uid = ?1
           UNION ALL
-           SELECT n.uid, n.parent_uid, n.name, anc.depth + 1
-           FROM nodes n JOIN anc ON n.uid = anc.parent_uid
+           SELECT n.parent_lid, n.parent_uid, n.name, anc.depth + 1
+           FROM nodes n JOIN anc ON n.lid = anc.parent_lid
           WHERE anc.depth < {MAX_PATH_DEPTH}
         )
         SELECT name, parent_uid FROM anc ORDER BY depth DESC"
@@ -32,6 +32,16 @@ pub enum Error {
    #[error("saved session can no longer unlock your keys — run `pdfs login` again")]
    ReloginRequired,

+    /// The account has a separate mailbox password that has not been entered
+    /// since login, so its keys cannot be unlocked. The fix is
+    /// [`auth::unlock`](crate::auth::unlock), not a new login.
+    #[error("account is locked — enter the mailbox password with `pdfs unlock`")]
+    Locked,
+
+    /// The mailbox password was checked against the account and is wrong.
+    #[error("that mailbox password does not unlock your account")]
+    WrongMailboxPassword,
+
    /// The login was gated behind human verification. Not a failure the user can
    /// fix by retrying: the challenge has to be solved and the login restarted
    /// with the resulting token (see [`auth::login_verified`](crate::auth::login_verified)).
@@ -199,9 +209,11 @@ impl From<serde_json::Error> for CoreError {
 impl From<Error> for CoreError {
    fn from(e: Error) -> Self {
        let kind = match &e {
-            Error::NotLoggedIn | Error::ReloginRequired | Error::HumanVerificationRequired(_) => {
-                ErrorKind::Denied
-            }
+            Error::NotLoggedIn
+            | Error::ReloginRequired
+            | Error::Locked
+            | Error::WrongMailboxPassword
+            | Error::HumanVerificationRequired(_) => ErrorKind::Denied,
            Error::Proton(proton_sdk::ProtonError::Api(api)) => api_kind(api.code),
            // A `ProtonError` that never reached the API is a transport failure.
            Error::Proton(_) => ErrorKind::Offline,
@@ -0,0 +1,204 @@
+//! A secret held in the Linux kernel keyring, for as long as the user is logged in.
+//!
+//! This is where the key passphrases of a two-password account live by default:
+//! the mailbox password is never stored, and the secrets derived from it are
+//! kept in kernel memory — not on disk, not in the Secret Service — and vanish
+//! when the user's last session ends or the machine reboots. Both the daemon and
+//! `pdfs unlock` reach the same entry because it hangs off the *user* keyring.
+//!
+//! Kernel keys are not paged to swap, are invisible to other users, and are
+//! wiped by [`clear`] (`KEYCTL_REVOKE`), which makes them a better home than a
+//! process's heap. Processes of the same user can still read them, exactly as
+//! they could ptrace the daemon: this protects against disk, backup and other
+//! users, not against code already running as you.
+//!
+//! The keyring may be unavailable (a container, a kernel built without
+//! `CONFIG_KEYS`); every operation then reports it as an error and the caller
+//! falls back to asking again, never to storing the secret somewhere weaker.
+
+use std::io;
+
+use zeroize::Zeroizing;
+
+/// Key description. Namespaced so it cannot collide with another program's key.
+#[cfg(not(test))]
+const DESCRIPTION: &[u8] = b"pdfs:key-passphrases\0";
+/// Tests must never touch a real unlock.
+#[cfg(test)]
+const DESCRIPTION: &[u8] = b"pdfs:key-passphrases:test\0";
+const KEY_TYPE: &[u8] = b"user\0";
+
+const KEY_SPEC_USER_KEYRING: i32 = -4;
+const KEYCTL_REVOKE: libc::c_long = 3;
+const KEYCTL_SETPERM: libc::c_long = 5;
+const KEYCTL_SEARCH: libc::c_long = 10;
+const KEYCTL_READ: libc::c_long = 11;
+
+/// Possessor and owner may view, read, write, search, link and set attributes;
+/// group and others get nothing.
+///
+/// A new key's default grants the owner only *view*, and read access to the
+/// possessor. A process possesses the user keyring only when its session
+/// keyring links to it, which a systemd user service or a container does not
+/// guarantee — so with the default, the daemon could store a key it then
+/// cannot read back. The owner is the same user that could ptrace the daemon
+/// anyway, so granting it read access gives up nothing.
+const PERM_OWNER_AND_POSSESSOR: u32 = 0x3f3f_0000;
+
+fn last_error<T>() -> io::Result<T> {
+    Err(io::Error::last_os_error())
+}
+
+fn find() -> io::Result<Option<libc::c_long>> {
+    // SAFETY: both strings are NUL-terminated and outlive the call.
+    let id = unsafe {
+        libc::syscall(
+            libc::SYS_keyctl,
+            KEYCTL_SEARCH,
+            KEY_SPEC_USER_KEYRING,
+            KEY_TYPE.as_ptr(),
+            DESCRIPTION.as_ptr(),
+            0,
+        )
+    };
+    if id >= 0 {
+        return Ok(Some(id));
+    }
+    let err = io::Error::last_os_error();
+    match err.raw_os_error() {
+        // ENOKEY: not stored. EKEYREVOKED/EKEYEXPIRED: stored once, now gone.
+        Some(libc::ENOKEY | libc::EKEYREVOKED | libc::EKEYEXPIRED) => Ok(None),
+        _ => Err(err),
+    }
+}
+
+/// Stop this process from being core-dumped or ptraced by an unprivileged
+/// process of the same user, so the secrets in its memory stay out of crash
+/// reports. Call once at start of a long-lived process that holds them.
+pub fn forbid_dumps() {
+    // SAFETY: `PR_SET_DUMPABLE` takes plain integers and only affects this process.
+    let rc = unsafe { libc::prctl(libc::PR_SET_DUMPABLE, 0, 0, 0, 0) };
+    if rc != 0 {
+        tracing::warn!(error = %io::Error::last_os_error(), "could not mark the process non-dumpable");
+    }
+}
+
+/// Store `secret`, replacing any earlier one.
+pub fn store(secret: &[u8]) -> io::Result<()> {
+    // SAFETY: strings are NUL-terminated; the payload pointer/length pair
+    // describes `secret`, which outlives the call.
+    let id = unsafe {
+        libc::syscall(
+            libc::SYS_add_key,
+            KEY_TYPE.as_ptr(),
+            DESCRIPTION.as_ptr(),
+            secret.as_ptr(),
+            secret.len(),
+            KEY_SPEC_USER_KEYRING,
+        )
+    };
+    if id < 0 {
+        return last_error();
+    }
+    // SAFETY: plain integer arguments.
+    let rc = unsafe {
+        libc::syscall(
+            libc::SYS_keyctl,
+            KEYCTL_SETPERM,
+            id,
+            PERM_OWNER_AND_POSSESSOR,
+        )
+    };
+    if rc < 0 {
+        // A key whose permissions are unknown is not one to leave behind.
+        let err = io::Error::last_os_error();
+        let _ = clear();
+        return Err(err);
+    }
+    Ok(())
+}
+
+/// Read the stored secret, or `None` when there is none.
+pub fn load() -> io::Result<Option<Zeroizing<Vec<u8>>>> {
+    let Some(id) = find()? else {
+        return Ok(None);
+    };
+    // Size first, then read; retry if the key was replaced in between.
+    for _ in 0..3 {
+        // SAFETY: a null buffer asks the kernel only for the payload length.
+        let len = unsafe {
+            libc::syscall(
+                libc::SYS_keyctl,
+                KEYCTL_READ,
+                id,
+                std::ptr::null_mut::<u8>(),
+                0usize,
+            )
+        };
+        if len < 0 {
+            return match io::Error::last_os_error().raw_os_error() {
+                Some(libc::ENOKEY | libc::EKEYREVOKED | libc::EKEYEXPIRED) => Ok(None),
+                _ => last_error(),
+            };
+        }
+        let mut buf = Zeroizing::new(vec![0u8; len as usize]);
+        // SAFETY: `buf` is `len` writable bytes.
+        let read = unsafe {
+            libc::syscall(
+                libc::SYS_keyctl,
+                KEYCTL_READ,
+                id,
+                buf.as_mut_ptr(),
+                buf.len(),
+            )
+        };
+        if read < 0 {
+            return last_error();
+        }
+        if read as usize <= buf.len() {
+            buf.truncate(read as usize);
+            return Ok(Some(buf));
+        }
+    }
+    Err(io::Error::other("the key changed while it was being read"))
+}
+
+/// Remove the stored secret. Succeeds when there is none.
+pub fn clear() -> io::Result<()> {
+    let Some(id) = find()? else {
+        return Ok(());
+    };
+    // SAFETY: plain integer arguments.
+    let rc = unsafe { libc::syscall(libc::SYS_keyctl, KEYCTL_REVOKE, id) };
+    if rc < 0 {
+        return match io::Error::last_os_error().raw_os_error() {
+            Some(libc::ENOKEY | libc::EKEYREVOKED) => Ok(()),
+            _ => last_error(),
+        };
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    // The kernel keyring is process-wide state and a sandbox may not offer it,
+    // so one test covers the whole round trip and skips when it is unavailable.
+    #[test]
+    fn stored_secret_round_trips_and_clears() {
+        if store(b"probe").is_err() {
+            eprintln!("kernel keyring unavailable; skipping");
+            return;
+        }
+        let saved = load().unwrap().expect("stored secret is readable");
+        assert_eq!(saved.as_slice(), b"probe");
+
+        store(b"replaced").unwrap();
+        assert_eq!(load().unwrap().unwrap().as_slice(), b"replaced");
+
+        clear().unwrap();
+        assert!(load().unwrap().is_none());
+        clear().unwrap();
+    }
+}
@@ -10,6 +10,7 @@ pub mod config;
 pub mod control;
 pub mod db;
 pub mod error;
+pub mod kernelkey;
 pub mod localindex;
 pub mod menu;
 pub mod mounts;
@@ -1,4 +1,4 @@
-//! The machine profile that travels with a device (features.md 5.3).
+//! The machine profile that travels with a device.
 //!
 //! Sync folder mappings, pins, and the settings that shape them live in
 //! `cache.db` and `config.json` — both on the local disk. When that disk dies,
@@ -55,9 +55,10 @@ fn systemctl_query(args: &[&str]) -> bool {
 /// keyring checks). `--now` is a no-op on an active unit, so the daemon would
 /// keep sleeping and the mount would not appear until the next poll fired.
 /// Restarting makes the new session take effect immediately, and starts the
-/// unit when it is not running at all.
+/// unit when it is not running at all. `reenable` for the reason given on
+/// [`enable`].
 pub fn enable_start() -> bool {
-    let enabled = systemctl(&["enable"]);
+    let enabled = systemctl(&["reenable"]);
    systemctl(&["restart"]) && enabled
 }

@@ -97,8 +98,14 @@ pub fn is_enabled() -> bool {
 /// Enable the service so it auto-starts on future logins, without necessarily
 /// starting it now beyond what `enable` does. Used by the Settings "Start on
 /// login" switch; pairs with [`disable`](disable).
+///
+/// `reenable` rather than `enable`: older installs were enabled
+/// into `default.target.wants`, and a plain `enable` would add the new
+/// `graphical-session.target.wants` link while leaving the old one to start the
+/// unit too early. `reenable` drops every existing link and recreates them from
+/// the current `[Install]` section.
 pub fn enable() -> bool {
-    systemctl(&["enable"])
+    systemctl(&["reenable"])
 }

 /// Disable auto-start without stopping the running mount. Used by the Settings
@@ -1,4 +1,4 @@
-//! Selective-sync ignore rules for mirror folders (features.md 1.1).
+//! Selective-sync ignore rules for mirror folders.
 //!
 //! A mirror folder otherwise uploads every path beneath its root, which for a
 //! project directory means `node_modules/`, `.git/`, and `target/` — quota
@@ -15,6 +15,7 @@ zip.workspace = true
 sha1.workspace = true
 proton-drive-rs.workspace = true
 futures.workspace = true
+async-trait.workspace = true
 tokio.workspace = true
 tracing.workspace = true
 fuser.workspace = true
@@ -24,3 +25,6 @@ base64.workspace = true
 image.workspace = true
 notify = "8"
 parking_lot.workspace = true
+
+[dev-dependencies]
+tracing-subscriber.workspace = true
@@ -9,7 +9,7 @@ use crate::shutdown::Shutdown;
 ///
 /// Returns whether this mount actually held the node, so the caller can evict
 /// its content blob once if *any* mount did.
-fn forget_and_notify(st: &mut State, notify: &mut NotifyBatch, uid: &NodeUid) -> bool {
+pub(crate) fn forget_and_notify(st: &mut State, notify: &mut NotifyBatch, uid: &NodeUid) -> bool {
    // Capture the inode before `forget` clears the uid mapping.
    let child = st.by_uid.get(uid).copied();
    let Some((parent, name)) = st.forget(uid) else {
@@ -97,15 +97,13 @@ fn event_serializes_shared_publication(event: &DriveEvent, own_volume: &VolumeId
 /// entry forces the next `lookup`/`readdir` to re-enumerate from the remote, so
 /// most events only need to invalidate listings rather than re-fetch eagerly.
 ///
-/// Applied to **every** mounted inode space, not just the primary one. This task
-/// is per-daemon while node state is per-mount, and a `DriveEvent` names a uid,
-/// not a mount — so a file trashed from another device has to be withdrawn from
-/// whichever of our sessions is showing it, which for anything under a sync
-/// folder is a [`Core::fork_state`] fork rather than `core.state`. Reaching for
-/// the primary state alone left forks serving a deleted file indefinitely, the
-/// read-side twin of `docs/BUGS.md` B74. Inode numbers are per-mount, so each
-/// mount must be notified through its **own** channel; that pairing is what
-/// [`Core::for_each_mount`] exists to preserve.
+/// Applied to the tree every mount shares, and told to **every** mounted
+/// session. A `DriveEvent` names a uid, not a mount, so a file trashed from
+/// another device has to be withdrawn from whichever of our sessions is showing
+/// it — which for anything under a sync folder is a [`Core::fork_state`] fork.
+/// Telling the primary session alone left forks serving a deleted file, the
+/// read-side twin of `docs/BUGS.md` B74. [`Core::for_each_mount`] sends what
+/// the kernel needs to hear to every session.
 fn apply_event(core: &Core, event: &DriveEvent, dirty: &mut DirtyParents) -> pdfs_core::Result<()> {
    let foreign_delete = is_foreign_node_delete(event, &core.primary_root_uid.volume_id);
    let serializes_shared_publication =
@@ -145,7 +143,7 @@ fn apply_event(core: &Core, event: &DriveEvent, dirty: &mut DirtyParents) -> pdf
            // create, and re-fetching would replace the size and mtime of the
            // write we just accepted with the stale revision's — making a file
            // that was copied in seconds ago read as empty until its upload
-            // lands (offline.md Phase 3).
+            // lands.
            //
            // A write that has already drained is the same story one step later:
            // the drain brought the tree level with the revision it sealed, so
@@ -233,6 +231,48 @@ fn acknowledge_applied_event(
    Ok(id)
 }

+/// How many applied node-update ids [`RecentEvents`] remembers. Far more than a
+/// replay can reach back: one comes from a batch whose last event was not its
+/// newest, so it repeats at most what that batch held.
+const RECENT_EVENTS: usize = 4096;
+
+/// The node updates applied lately, by event id, so one that comes round again
+/// is skipped rather than applied twice.
+///
+/// The feed can deliver the same event twice in a batch, and a batch whose
+/// events come out of order leaves the cursor short of its newest event, so the
+/// next poll replays what lay past it. An update applied twice is not harmless:
+/// the first copy of our own change claims the echo [`Core::note_self_change`]
+/// recorded, and the second, unclaimed, reads as someone else's edit and evicts
+/// the bytes a partial write is about to gap-fill from (docs/BUGS.md B123).
+///
+/// Only node updates: a delete is idempotent, and a continuity loss names the
+/// cursor it lost, which is an id already applied.
+#[derive(Default)]
+struct RecentEvents {
+    ids: HashSet<DriveEventId>,
+    order: VecDeque<DriveEventId>,
+}
+
+impl RecentEvents {
+    /// Record `event` as applied, reporting whether it was already.
+    fn repeat(&mut self, event: &DriveEvent) -> bool {
+        let DriveEvent::NodeUpdated { id, .. } = event else {
+            return false;
+        };
+        if !self.ids.insert(id.clone()) {
+            return true;
+        }
+        self.order.push_back(id.clone());
+        if self.order.len() > RECENT_EVENTS
+            && let Some(old) = self.order.pop_front()
+        {
+            self.ids.remove(&old);
+        }
+        false
+    }
+}
+
 /// The folders one batch of events changed, collected so the listings are
 /// dropped once at the end of the batch rather than once per event.
 ///
@@ -320,10 +360,10 @@ fn flush_dirty_parents(core: &Core, dirty: &DirtyParents) {
 /// only on fatal error.
 ///
 /// Takes the whole `Core` rather than the primary mount's pieces: an event has
-/// to be applied to every mounted inode space, and the registry that enumerates
-/// them lives on the `Core` (see [`apply_event`]).
+/// to reach every mounted session, and the registry that enumerates them lives
+/// on the `Core` (see [`apply_event`]).
 pub(super) async fn run_event_sync(
-    client: ProtonDriveClient,
+    client: Arc<dyn DriveApi>,
    scope: DriveEventScopeId,
    core: Core,
 ) {
@@ -335,7 +375,7 @@ pub(super) async fn run_event_sync(
        // server head; persist it so the next restart resumes instead of
        // reseeding (which would skip everything that changed offline).
        // Seeding needs the network, and this task also runs on mounts that
-        // started offline (offline.md Phase 1) — so retry rather than giving up,
+        // started offline — so retry rather than giving up,
        // which used to disable live sync for the life of the daemon.
        Ok(None) => {
            // Nothing says what changed before this cursor, so a persisted SDK
@@ -377,10 +417,12 @@ pub(super) async fn run_event_sync(
    };
    info!(?cursor, "event sync started");

+    let mut recent = RecentEvents::default();
    loop {
-        tokio::time::sleep(POLL_INTERVAL).await;
-        let events = match client.enumerate_events(&scope, cursor.as_ref()).await {
+        core.next_poll(POLL_INTERVAL).await;
+        let events = match link::bounded(client.enumerate_events(&scope, cursor.as_ref())).await {
            Ok(events) => events,
+            Err(e) if core.lost_link(&e, "poll events") => continue,
            Err(e) => {
                warn!(error = %e, "event poll failed; retrying after interval");
                continue;
@@ -396,6 +438,11 @@ pub(super) async fn run_event_sync(
        // did apply.
        let mut dirty = DirtyParents::default();
        for event in &events {
+            if recent.repeat(event) {
+                debug!(id = %event.id().as_str(), "skipping an event already applied");
+                cursor = Some(event.id().clone());
+                continue;
+            }
            // Converge the SDK's own caches (folder keys, entity cache) on the
            // server before applying the event to our tree. Without this, a node
            // re-keyed/moved by another client keeps a stale key in the SDK for
@@ -471,9 +518,10 @@ pub(super) async fn run_photos_event_sync(core: Core) {
    info!(?cursor, "photo event sync started");

    loop {
-        tokio::time::sleep(POLL_INTERVAL).await;
-        let events = match photos.enumerate_events(&scope, cursor.as_ref()).await {
+        core.next_poll(POLL_INTERVAL).await;
+        let events = match link::bounded(photos.enumerate_events(&scope, cursor.as_ref())).await {
            Ok(events) => events,
+            Err(error) if core.lost_link(&error, "poll photo events") => continue,
            Err(error) => {
                warn!(%error, "photo event poll failed; retrying after interval");
                continue;
@@ -612,7 +660,7 @@ pub(super) fn run_local_index(
            scan_local_once(&db, &indexing, &transfers, &mountpoint);
        }
        // Interruptible, so teardown joins this thread instead of leaving it to
-        // keep rewriting the index for a mount that is gone (bugs.md B44).
+        // keep rewriting the index for a mount that is gone (`docs/BUGS.md` B44).
        if !shutdown.sleep(LOCAL_INDEX_CHECK) {
            return;
        }
@@ -715,6 +763,43 @@ mod tests {
        }
    }

+    #[test]
+    fn a_node_update_seen_again_is_skipped_but_other_events_are_not() {
+        let update = |id: &str| DriveEvent::NodeUpdated {
+            id: DriveEventId::from(id),
+            node_uid: uid("file"),
+            parent_node_uid: None,
+            is_trashed: false,
+            is_shared: false,
+        };
+        let mut recent = RecentEvents::default();
+        assert!(!recent.repeat(&update("e1")));
+        assert!(!recent.repeat(&update("e2")));
+        assert!(recent.repeat(&update("e1")), "a duplicate or replay");
+        let lost = DriveEvent::ContinuityLost {
+            id: DriveEventId::from("e2"),
+        };
+        assert!(!recent.repeat(&lost), "names the cursor, which was applied");
+    }
+
+    #[test]
+    fn recent_events_forget_the_oldest_past_their_bound() {
+        let update = |n: usize| DriveEvent::NodeUpdated {
+            id: DriveEventId::from(format!("e{n}")),
+            node_uid: uid("file"),
+            parent_node_uid: None,
+            is_trashed: false,
+            is_shared: false,
+        };
+        let mut recent = RecentEvents::default();
+        for n in 0..=RECENT_EVENTS {
+            assert!(!recent.repeat(&update(n)));
+        }
+        assert_eq!(recent.ids.len(), RECENT_EVENTS);
+        assert!(!recent.repeat(&update(0)), "the oldest was forgotten");
+        assert!(recent.repeat(&update(RECENT_EVENTS)));
+    }
+
    #[test]
    fn foreign_delete_invalidates_an_earlier_refresh_generation() {
        let own_volume = VolumeId::from("own");
@@ -163,8 +163,8 @@ fn read_request_line(reader: &mut impl BufRead) -> std::io::Result<Option<String
 /// Turn a CLI-supplied path into the mount that owns it and the path relative
 /// to *that* mount's root.
 ///
-/// [`rel_to_mount`] is the older, primary-only reading, and it is what every
-/// mutating request still uses. It rejects anything outside the primary
+/// [`rel_to_mount`] is the older, primary-only reading, and it is what most
+/// requests still use. It rejects anything outside the primary
 /// mountpoint, which leaves a secondary on-demand mount — a synced folder
 /// switched out of mirror mode — with no way to be named at all: `pdfs ls` and
 /// `pdfs refresh` both answered "is not under the mountpoint", so a folder
@@ -185,11 +185,14 @@ fn route_to_mount(core: &Core, mountpoint: &Path, path: &str) -> CoreResult<(Cor
    rel_to_mount(mountpoint, path).map(|rel| (core.clone(), rel))
 }

-/// [`route_to_mount`] for a conflict copy. The listing names a copy inside a
-/// synced folder by its absolute local path (`docs/BUGS.md` B99), so the
-/// resolve has to run against the on-demand mount serving it. A mirror folder
-/// has no mount to run against: its copy is an ordinary local file.
-fn route_conflict(core: &Core, mountpoint: &Path, path: &str) -> CoreResult<(Core, PathBuf)> {
+/// [`route_to_mount`] for a request that changes what it names: trash, rename,
+/// create a folder, resolve a conflict. Each has to run against the on-demand
+/// mount serving the path, and `pdfs rm ~/Downloads/x` answered "is not under
+/// the mountpoint" while `pdfs move` took the same path. The conflict listing
+/// names a copy in a synced folder by its absolute local path (`docs/BUGS.md`
+/// B99), so resolving one needs this too. A mirror folder has no mount to run
+/// against: a file there is an ordinary local file.
+fn route_change(core: &Core, mountpoint: &Path, path: &str) -> CoreResult<(Core, PathBuf)> {
    let routed = route_to_mount(core, mountpoint, path).map_err(|e| {
        let p = Path::new(path);
        let mirrored = core
@@ -200,7 +203,7 @@ fn route_conflict(core: &Core, mountpoint: &Path, path: &str) -> CoreResult<(Cor
            .any(|folder| folder.mode == "mirror" && p.starts_with(&folder.local_path));
        if mirrored {
            CoreError::invalid(format!(
-                "{path} is in a mirrored folder; rename or delete the local file there"
+                "{path} is in a mirrored folder; change the local file there instead"
            ))
        } else {
            e
@@ -217,6 +220,27 @@ fn route_conflict(core: &Core, mountpoint: &Path, path: &str) -> CoreResult<(Cor
    }
 }

+/// [`route_change`] for a request that trashes or renames the node it names.
+/// A mount's root is My files or a whole synced folder. An on-demand folder's
+/// root has a parent on Drive, so nothing further down would stop `pdfs rm
+/// ~/Downloads` from trashing the folder out from under its own mount.
+fn route_node(core: &Core, mountpoint: &Path, path: &str) -> CoreResult<(Core, PathBuf)> {
+    let routed = route_change(core, mountpoint, path)?;
+    if below_root(&routed.1) {
+        Ok(routed)
+    } else {
+        Err(CoreError::invalid(format!(
+            "{path} is the root of a synced location and cannot be changed"
+        )))
+    }
+}
+
+/// Whether a mount-relative path names something below the mount's root.
+fn below_root(rel: &Path) -> bool {
+    rel.components()
+        .any(|component| matches!(component, Component::Normal(_)))
+}
+
 /// Turn a CLI-supplied path into a mountpoint-relative path. An absolute path
 /// must live under `mountpoint`; a relative path is taken as already relative to
 /// the mount root.
@@ -291,6 +315,9 @@ impl Drop for RefreshGuard {
 pub(crate) fn status_response(core: &Core, username: &str, mountpoint: &Path) -> CtlResponse {
    let pins = core.cache.list_pins();
    let queued = core.db.pending_op_counts().unwrap_or_default();
+    // Read after the queue: the drain counts an upload as landing before it
+    // retires the op, so one of the two always has it (B119).
+    let landing = core.landing_uploads.load(Ordering::SeqCst);
    let staging = core.cache.staging_usage();
    CtlResponse::Status {
        parked_uploads: queued.parked.max(0) as u64,
@@ -307,7 +334,7 @@ pub(crate) fn status_response(core: &Core, username: &str, mountpoint: &Path) ->
        budget: core.cache.budget(),
        pins,
        online: core.online.load(Ordering::Relaxed),
-        pending_uploads: queued.uploads.max(0) as u64,
+        pending_uploads: queued.uploads.max(0) as u64 + landing,
        pending_changes: queued.changes.max(0) as u64,
    }
 }
@@ -350,6 +377,7 @@ fn touched_topics(request: &CtlRequest) -> &'static [Topic] {
        | R::RestoreSyncFolders { .. }
        | R::RestoreDeviceFolders { .. } => &[Topic::Locations, Topic::Devices],
        R::RetryPendingOp { .. } => &[Topic::Queue],
+        R::DiscardPendingOp { .. } => &[Topic::Queue, Topic::Files],
        R::ResolveConflict { .. } => &[Topic::Files, Topic::Trash, Topic::Conflicts],
        R::ShareNode { .. }
        | R::ShareNodeByUid { .. }
@@ -959,8 +987,8 @@ fn handle_control_conn(core: &Core, username: &str, mountpoint: &Path, stream: U
            },
            Err(e) => CtlResponse::error(e),
        },
-        Ok(CtlRequest::Rename { path, new_name }) => match rel_to_mount(mountpoint, &path) {
-            Ok(rel) => match core.rename(&rel, &new_name) {
+        Ok(CtlRequest::Rename { path, new_name }) => match route_node(core, mountpoint, &path) {
+            Ok((core, rel)) => match core.rename(&rel, &new_name) {
                Ok(name) => {
                    core.log_activity(ActivityKind::Rename, &name, format!("was {path}"), true);
                    CtlResponse::Ok {
@@ -974,6 +1002,24 @@ fn handle_control_conn(core: &Core, username: &str, mountpoint: &Path, stream: U
            },
            Err(e) => CtlResponse::error(e),
        },
+        // Two absolute paths may name two different locations, which only
+        // `move_between` can resolve; a relative pair keeps the old meaning.
+        Ok(CtlRequest::Move { path, new_parent })
+            if Path::new(&path).is_absolute() && Path::new(&new_parent).is_absolute() =>
+        {
+            match core.move_between(Path::new(&path), Path::new(&new_parent)) {
+                Ok(name) => {
+                    core.log_activity(ActivityKind::Move, &name, format!("to {new_parent}"), true);
+                    CtlResponse::Ok {
+                        message: format!("moved {name}"),
+                    }
+                }
+                Err(e) => {
+                    core.log_activity(ActivityKind::Move, &path, &e, false);
+                    CtlResponse::error(e)
+                }
+            }
+        }
        Ok(CtlRequest::Move { path, new_parent }) => {
            match (
                rel_to_mount(mountpoint, &path),
@@ -999,8 +1045,8 @@ fn handle_control_conn(core: &Core, username: &str, mountpoint: &Path, stream: U
                (Err(e), _) | (_, Err(e)) => CtlResponse::error(e),
            }
        }
-        Ok(CtlRequest::Delete { path }) => match rel_to_mount(mountpoint, &path) {
-            Ok(rel) => match core.delete(&rel) {
+        Ok(CtlRequest::Delete { path }) => match route_node(core, mountpoint, &path) {
+            Ok((core, rel)) => match core.delete(&rel) {
                Ok(name) => {
                    core.log_activity(ActivityKind::Trash, &name, "", true);
                    CtlResponse::Ok {
@@ -1014,21 +1060,23 @@ fn handle_control_conn(core: &Core, username: &str, mountpoint: &Path, stream: U
            },
            Err(e) => CtlResponse::error(e),
        },
-        Ok(CtlRequest::CreateFolder { parent, name }) => match rel_to_mount(mountpoint, &parent) {
-            Ok(parent_rel) => match core.create_folder(&parent_rel, &name) {
-                Ok(name) => {
-                    core.log_activity(ActivityKind::CreateFolder, &name, "", true);
-                    CtlResponse::Ok {
-                        message: format!("created folder {name}"),
+        Ok(CtlRequest::CreateFolder { parent, name }) => {
+            match route_change(core, mountpoint, &parent) {
+                Ok((core, parent_rel)) => match core.create_folder(&parent_rel, &name) {
+                    Ok(name) => {
+                        core.log_activity(ActivityKind::CreateFolder, &name, "", true);
+                        CtlResponse::Ok {
+                            message: format!("created folder {name}"),
+                        }
                    }
-                }
-                Err(e) => {
-                    core.log_activity(ActivityKind::CreateFolder, &name, &e, false);
-                    CtlResponse::error(e)
-                }
-            },
-            Err(e) => CtlResponse::error(e),
-        },
+                    Err(e) => {
+                        core.log_activity(ActivityKind::CreateFolder, &name, &e, false);
+                        CtlResponse::error(e)
+                    }
+                },
+                Err(e) => CtlResponse::error(e),
+            }
+        }
        Ok(CtlRequest::UploadPaths { parent, sources }) => {
            match rel_to_mount(mountpoint, &parent) {
                // Ack immediately and upload on a background thread: a directory tree
@@ -1345,7 +1393,7 @@ fn handle_control_conn(core: &Core, username: &str, mountpoint: &Path, stream: U
            Err(e) => CtlResponse::error(e),
        },
        Ok(CtlRequest::ResolveConflict { path, keep }) => {
-            match route_conflict(core, mountpoint, &path) {
+            match route_change(core, mountpoint, &path) {
                Ok((core, rel)) => match core.resolve_conflict(&rel, &keep) {
                    Ok(message) => CtlResponse::Ok { message },
                    Err(e) => CtlResponse::error(e),
@@ -1357,6 +1405,20 @@ fn handle_control_conn(core: &Core, username: &str, mountpoint: &Path, stream: U
            Ok(items) => CtlResponse::PendingOps { items },
            Err(e) => CtlResponse::error(e),
        },
+        Ok(CtlRequest::ExportPendingOp { id, dest }) => {
+            match core.export_pending_op(id, Path::new(&dest)) {
+                Ok(written) => CtlResponse::Ok {
+                    message: format!("wrote {} to {dest}", human_bytes(written)),
+                },
+                Err(e) => CtlResponse::error(e),
+            }
+        }
+        Ok(CtlRequest::DiscardPendingOp { id }) => match core.discard_pending_op(id) {
+            Ok(path) => CtlResponse::Ok {
+                message: format!("discarded the queued change to {path}"),
+            },
+            Err(e) => CtlResponse::error(e),
+        },
        Ok(CtlRequest::RetryPendingOp { id }) => match core.retry_pending_ops(id) {
            Ok(0) if id.is_some() => CtlResponse::Ok {
                message: "nothing to retry: the operation is already due or waiting for a rename"
@@ -1754,7 +1816,7 @@ pub(crate) fn run_control_socket(
    info!("control socket listening");
    for conn in listener.incoming() {
        // Checked on every accept, including the deliberate poke teardown sends
-        // to wake this thread out of a blocking accept (bugs.md B44).
+        // to wake this thread out of a blocking accept (`docs/BUGS.md` B44).
        if core.shutdown.is_stopping() {
            info!("control socket closing");
            return;
@@ -1846,6 +1908,18 @@ mod request_limit_tests {
        assert!(rel_to_mount(mountpoint, "Photos/../../escape").is_err());
        assert!(rel_to_mount(mountpoint, "/mnt/elsewhere").is_err());
    }
+
+    /// `pdfs rm` and `pdfs rename` reach on-demand mounts, whose root is a whole
+    /// synced folder with a parent on Drive. Only a path below a root may get
+    /// through to the trash or rename call.
+    #[test]
+    fn only_a_path_below_a_mount_root_names_a_node() {
+        assert!(below_root(Path::new("Photos")));
+        assert!(below_root(Path::new("./Photos/2026")));
+        assert!(!below_root(Path::new("")));
+        assert!(!below_root(Path::new(".")));
+        assert!(!below_root(Path::new("./.")));
+    }
 }

 #[cfg(test)]
@@ -1,5 +1,5 @@
 //! This machine as a Proton Drive Device, and the local folders it keeps in
-//! step with the remote (devices.md).
+//! step with the remote.
 //!
 //! A sync folder runs in one of two modes. `mirror` keeps a real local tree that
 //! the engine in [`super::sync`] reconciles both ways; `ondemand` evicts that
@@ -27,7 +27,7 @@ use tracing::{info, warn};

 use super::sync::{self, base_name};
 use super::{
-    Core, SecondaryInsertRejection, SecondaryMount, State, SwitchBlocked, clear_stale_mount,
+    Core, SecondaryInsertRejection, SecondaryMount, SwitchBlocked, clear_stale_mount,
    device_type_str, dir_is_empty, evict_dir_contents, fuse_connection_id, is_stale_mount,
    now_secs, parse_uid, spawn_session, sync_folder_info, this_hostname,
 };
@@ -184,8 +184,8 @@ impl Core {
    }

    /// Adopt an existing device as *this* machine's, pinning it in `config.json`
-    /// so hostname changes and reinstalls stop registering duplicates
-    /// (features.md 5.1). `None` clears the pin and returns to hostname matching.
+    /// so hostname changes and reinstalls stop registering duplicates.
+    /// `None` clears the pin and returns to hostname matching.
    ///
    /// Refuses a uid that is not in the account: the whole point of the pin is
    /// that it is authoritative, so accepting a bad one would defer the failure
@@ -260,7 +260,7 @@ impl Core {
        })
    }

-    // ---- device folder sync (devices.md, Phase 1) -------------------------
+    // ---- device folder sync -------------------------

    /// Auto-register (or recover) this machine as a Proton Drive Device, caching
    /// it so restarts reuse the same device. Recovery matches an existing remote
@@ -270,8 +270,7 @@ impl Core {
    /// Resolution order: the *adopted* uid pinned in `config.json`, then the
    /// cached DB row (validated remotely), then a hostname match, then create.
    /// The pin exists because the hostname heuristic silently registers a second
-    /// device after a rename or reinstall, orphaning the first one's folders
-    /// (features.md 5.1).
+    /// device after a rename or reinstall, orphaning the first one's folders.
    pub(crate) fn ensure_device(&self) -> CoreResult<StoredDevice> {
        let name = this_hostname();
        // Enumerate the remote devices once: used to validate the pin, validate
@@ -363,14 +362,14 @@ impl Core {
    ) -> CoreResult<Option<NodeUid>> {
        let uids = self
            .rt
-            .block_on(self.client.enumerate_folder_children_node_uids(root_uid))
+            .block_on(self.drive.enumerate_folder_children_node_uids(root_uid))
            .map_err(|e| CoreError::from_api(&e, "list device root"))?;
        if uids.is_empty() {
            return Ok(None);
        }
        let nodes = self
            .rt
-            .block_on(self.client.enumerate_nodes(&uids))
+            .block_on(self.drive.enumerate_nodes(&uids))
            .map_err(|e| CoreError::from_api(&e, "resolve device root children"))?;
        Ok(nodes
            .into_iter()
@@ -446,10 +445,7 @@ impl Core {
            }
            None => self
                .rt
-                .block_on(
-                    self.client
-                        .create_folder(&root_uid, &name, Some(now_secs())),
-                )
+                .block_on(self.drive.create_folder(&root_uid, &name, Some(now_secs())))
                .map_err(|e| CoreError::from_api(&e, &format!("create device folder {name}")))?,
        };

@@ -603,7 +599,7 @@ impl Core {
            && let Some(uid) = parse_uid(&folder.remote_uid)
            && let Err(e) = self
                .rt
-                .block_on(self.client.trash_nodes(&[uid]))
+                .block_on(self.drive.trash_nodes(&[uid]))
                .and_then(batch::into_unit)
        {
            warn!(id, error = %e, "delete remote device folder failed");
@@ -619,23 +615,16 @@ impl Core {
        };
    }

-    /// A sibling Core that shares this one's client/rt/cache/db (and transfer,
-    /// activity, mount registries) but gets a **fresh, empty `State`** — its own
-    /// inode space starting at [`ROOT_INO`]. Used to root a secondary FUSE session
-    /// at an `ondemand` sync folder without colliding with the main mount's inodes
-    /// (devices.md Phase 3).
+    /// A sibling Core for a secondary FUSE session rooted at an `ondemand` sync
+    /// folder. It shares everything with this one,
+    /// the tree included, except what belongs to a session: its root and its
+    /// kernel channel, both filled in when the session is built.
    pub(crate) fn fork_state(&self) -> Core {
        let mut fork = self.clone();
        fork.primary = false;
-        let share_access = self.state().share_access.clone();
-        fork.state = Arc::new(Mutex::new(State::new(self.db.clone(), share_access, 2)));
-        // A fresh inode space needs a fresh notification channel: this fork's
-        // session is the only one that knows these inodes, so it must be the one
-        // notified about them. Filled in by `spawn_ondemand_mount`.
+        fork.root = Arc::new(OnceLock::new());
        fork.notifier = Arc::new(OnceLock::new());
        fork.session_live = Arc::new(std::sync::atomic::AtomicBool::new(false));
-        // Size upgrades are keyed by inode, which is per-fork too.
-        fork.size_upgrades = Arc::new(Mutex::new(HashMap::new()));
        fork
    }

@@ -858,7 +847,7 @@ impl Core {
                })?;
                let root = self
                    .rt
-                    .block_on(self.client.enumerate_nodes(std::slice::from_ref(&root_uid)))
+                    .block_on(self.drive.enumerate_nodes(std::slice::from_ref(&root_uid)))
                    .map_err(|e| SwitchBlocked::Failed(format!("fetch remote root: {e}")))?
                    .into_iter()
                    .next()
@@ -937,8 +926,8 @@ impl Core {
        }
    }

-    /// Spawn a secondary FUSE session rooted at `root` over `local` on a forked
-    /// inode space. Clears any stale kernel mount first (a crashed run can leave
+    /// Spawn a secondary FUSE session rooted at `root` over `local` from a
+    /// [`Core::fork_state`] sibling. Clears any stale kernel mount first (a crashed run can leave
    /// one, which would fail the fresh mount with EBUSY).
    pub(crate) fn spawn_ondemand_mount(
        &self,
@@ -996,8 +985,7 @@ impl Core {
    /// restart (their local dirs are empty on disk — the files live in the cloud).
    /// Best-effort per folder: a missing local path or a failed remote fetch marks
    /// the folder `error` and moves on rather than aborting the rest. Runs on its
-    /// own thread from `mount` so the network fetches never block startup
-    /// (devices.md Phase 4).
+    /// own thread from `mount` so the network fetches never block startup.
    pub(crate) fn restore_ondemand_mounts(&self) {
        let folders = match self.db.sync_folder_list() {
            Ok(f) => f,
@@ -1017,7 +1005,7 @@ impl Core {
            };
            let root = match self
                .rt
-                .block_on(self.client.enumerate_nodes(std::slice::from_ref(&root_uid)))
+                .block_on(self.drive.enumerate_nodes(std::slice::from_ref(&root_uid)))
            {
                Ok(v) => match v.into_iter().next() {
                    Some(n) => n,
@@ -0,0 +1,473 @@
+//! The calls the sync core makes to Drive, behind a trait.
+//!
+//! `Core` used to hold a concrete [`ProtonDriveClient`], so no test could make
+//! Drive answer late, answer stale, or not answer at all, and the interleavings
+//! behind most recent bugs could only be found on a real account over a slow
+//! link. [`DriveApi`] is the part of the
+//! client the mount, the drain, the event feed and the mirror engine use; the
+//! real client implements it by forwarding, and the simulation tests implement
+//! it with an in-memory Drive that injects Drive's known faults.
+//!
+//! Sharing, Photos, devices, invitations and public links stay on the concrete
+//! client (`Core::client`) until a test needs them faked.
+//!
+//! The method names match the client's own, so a call site reads the same
+//! whichever it goes through. The client's generic methods (a reader or writer
+//! of any type) cannot be part of an object-safe trait, so the trait takes them
+//! as trait objects and `impl dyn DriveApi` puts the generic signatures back.
+
+use std::io::{Read, Write};
+use std::sync::Arc;
+
+use async_trait::async_trait;
+use futures::StreamExt as _;
+use futures::stream::BoxStream;
+use proton_drive_rs::proton_sdk::account::Quota;
+use proton_drive_rs::proton_sdk::error::Result;
+use proton_drive_rs::proton_sdk::ids::{DriveEventId, NodeUid};
+use proton_drive_rs::{
+    DriveEvent, DriveEventScopeId, Node, NodeMoveItem, ProtonDriveClient, RevisionReader, Thumbnail,
+};
+
+/// One outcome per node of a batch request; see [`ProtonDriveClient::trash_nodes`].
+pub(crate) type NodeOutcomes = Vec<(NodeUid, Result<()>)>;
+
+/// The outcomes of a streaming batch request, one item per node as it lands.
+pub(crate) type OutcomeStream<'a> = BoxStream<'a, Result<(NodeUid, Result<()>)>>;
+
+/// Drive as the sync core sees it. See the module documentation.
+#[async_trait]
+pub(crate) trait DriveApi: Send + Sync {
+    async fn get_my_files_folder(&self) -> Result<Node>;
+
+    async fn get_node(&self, uid: &NodeUid) -> Result<Option<Node>>;
+
+    async fn enumerate_nodes(&self, uids: &[NodeUid]) -> Result<Vec<Node>>;
+
+    /// As [`DriveApi::enumerate_nodes`], but files carry no claimed size or
+    /// modification time; see [`ProtonDriveClient::enumerate_nodes_light`].
+    async fn enumerate_nodes_light(&self, uids: &[NodeUid]) -> Result<Vec<Node>>;
+
+    async fn enumerate_folder_children_node_uids(
+        &self,
+        folder_uid: &NodeUid,
+    ) -> Result<Vec<NodeUid>>;
+
+    async fn enumerate_events(
+        &self,
+        scope: &DriveEventScopeId,
+        cursor: Option<&DriveEventId>,
+    ) -> Result<Vec<DriveEvent>>;
+
+    async fn invalidate_caches_for_event(&self, event: &DriveEvent) -> Result<()>;
+
+    async fn create_folder(
+        &self,
+        parent_uid: &NodeUid,
+        name: &str,
+        last_modification_time: Option<i64>,
+    ) -> Result<NodeUid>;
+
+    async fn upload_file(
+        &self,
+        parent_uid: &NodeUid,
+        name: &str,
+        media_type: &str,
+        contents: &[u8],
+    ) -> Result<NodeUid>;
+
+    #[allow(clippy::too_many_arguments)]
+    async fn upload_file_from_dyn(
+        &self,
+        parent_uid: &NodeUid,
+        name: &str,
+        media_type: &str,
+        reader: &mut (dyn Read + Send),
+        intended_size: i64,
+        thumbnails: Vec<Thumbnail>,
+        last_modification_time: Option<i64>,
+        aead: bool,
+    ) -> Result<NodeUid>;
+
+    #[allow(clippy::too_many_arguments)]
+    async fn upload_file_replacing_draft_from_dyn(
+        &self,
+        parent_uid: &NodeUid,
+        name: &str,
+        media_type: &str,
+        reader: &mut (dyn Read + Send),
+        intended_size: i64,
+        thumbnails: Vec<Thumbnail>,
+        last_modification_time: Option<i64>,
+        aead: bool,
+    ) -> Result<NodeUid>;
+
+    async fn upload_new_revision_from_dyn(
+        &self,
+        file_uid: &NodeUid,
+        reader: &mut (dyn Read + Send),
+        intended_size: i64,
+        thumbnails: Vec<Thumbnail>,
+        last_modification_time: Option<i64>,
+    ) -> Result<()>;
+
+    async fn open_revision(&self, uid: &NodeUid) -> Result<Arc<dyn RevisionRead>>;
+
+    async fn download_file_to_dyn(
+        &self,
+        uid: &NodeUid,
+        output: &mut (dyn Write + Send),
+    ) -> Result<()>;
+
+    async fn download_revision_to_dyn(
+        &self,
+        file_uid: &NodeUid,
+        revision_id: &str,
+        writer: &mut (dyn Write + Send),
+    ) -> Result<()>;
+
+    async fn rename_node(
+        &self,
+        uid: &NodeUid,
+        new_name: &str,
+        new_media_type: Option<&str>,
+    ) -> Result<()>;
+
+    async fn move_node(&self, uid: &NodeUid, new_parent: &NodeUid) -> Result<()>;
+
+    fn move_nodes_streaming<'a>(
+        &'a self,
+        items: Vec<NodeMoveItem>,
+        new_parent: NodeUid,
+    ) -> OutcomeStream<'a>;
+
+    async fn trash_nodes(&self, uids: &[NodeUid]) -> Result<NodeOutcomes>;
+
+    async fn restore_nodes(&self, uids: &[NodeUid]) -> Result<NodeOutcomes>;
+
+    fn restore_nodes_streaming<'a>(&'a self, uids: &[NodeUid]) -> OutcomeStream<'a>;
+
+    fn delete_nodes_streaming<'a>(&'a self, uids: &[NodeUid]) -> OutcomeStream<'a>;
+
+    async fn enumerate_trash_node_uids(&self) -> Result<Vec<NodeUid>>;
+
+    /// The account's storage, across every Proton product.
+    async fn quota(&self) -> Result<Quota>;
+
+    /// Called by the drain once it has let go of the blob of an upload to
+    /// `uid` that landed, or retired the create that made `uid`, before the
+    /// tree has the node, so a simulation can hold it there. Blocks the drain
+    /// worker it is called on.
+    #[cfg(test)]
+    fn landing(&self, _uid: &NodeUid) {}
+}
+
+/// The generic signatures of the client, over the object-safe ones above.
+impl dyn DriveApi {
+    #[allow(clippy::too_many_arguments)]
+    pub(crate) async fn upload_file_from<R: Read + Send>(
+        &self,
+        parent_uid: &NodeUid,
+        name: &str,
+        media_type: &str,
+        mut reader: R,
+        intended_size: i64,
+        thumbnails: Vec<Thumbnail>,
+        last_modification_time: Option<i64>,
+        aead: bool,
+    ) -> Result<NodeUid> {
+        self.upload_file_from_dyn(
+            parent_uid,
+            name,
+            media_type,
+            &mut reader,
+            intended_size,
+            thumbnails,
+            last_modification_time,
+            aead,
+        )
+        .await
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    pub(crate) async fn upload_file_replacing_draft_from<R: Read + Send>(
+        &self,
+        parent_uid: &NodeUid,
+        name: &str,
+        media_type: &str,
+        mut reader: R,
+        intended_size: i64,
+        thumbnails: Vec<Thumbnail>,
+        last_modification_time: Option<i64>,
+        aead: bool,
+    ) -> Result<NodeUid> {
+        self.upload_file_replacing_draft_from_dyn(
+            parent_uid,
+            name,
+            media_type,
+            &mut reader,
+            intended_size,
+            thumbnails,
+            last_modification_time,
+            aead,
+        )
+        .await
+    }
+
+    pub(crate) async fn upload_new_revision_from<R: Read + Send>(
+        &self,
+        file_uid: &NodeUid,
+        mut reader: R,
+        intended_size: i64,
+        thumbnails: Vec<Thumbnail>,
+        last_modification_time: Option<i64>,
+    ) -> Result<()> {
+        self.upload_new_revision_from_dyn(
+            file_uid,
+            &mut reader,
+            intended_size,
+            thumbnails,
+            last_modification_time,
+        )
+        .await
+    }
+
+    pub(crate) async fn download_file_to<W: Write + Send>(
+        &self,
+        uid: &NodeUid,
+        output: &mut W,
+    ) -> Result<()> {
+        self.download_file_to_dyn(uid, output).await
+    }
+
+    pub(crate) async fn download_revision_to<W: Write + Send>(
+        &self,
+        file_uid: &NodeUid,
+        revision_id: &str,
+        writer: &mut W,
+    ) -> Result<()> {
+        self.download_revision_to_dyn(file_uid, revision_id, writer)
+            .await
+    }
+}
+
+/// An open revision that block reads are served from; see [`RevisionReader`].
+#[async_trait]
+pub(crate) trait RevisionRead: Send + Sync {
+    /// Plaintext size of the revision.
+    fn size(&self) -> u64;
+
+    /// Plaintext size of each block, in block order.
+    fn block_sizes(&self) -> &[u64];
+
+    async fn read_at(&self, offset: u64, length: u64) -> Result<Vec<u8>>;
+}
+
+#[async_trait]
+impl RevisionRead for RevisionReader {
+    fn size(&self) -> u64 {
+        RevisionReader::size(self)
+    }
+
+    fn block_sizes(&self) -> &[u64] {
+        RevisionReader::block_sizes(self)
+    }
+
+    async fn read_at(&self, offset: u64, length: u64) -> Result<Vec<u8>> {
+        RevisionReader::read_at(self, offset, length).await
+    }
+}
+
+#[async_trait]
+impl DriveApi for ProtonDriveClient {
+    async fn get_my_files_folder(&self) -> Result<Node> {
+        ProtonDriveClient::get_my_files_folder(self).await
+    }
+
+    async fn get_node(&self, uid: &NodeUid) -> Result<Option<Node>> {
+        ProtonDriveClient::get_node(self, uid).await
+    }
+
+    async fn enumerate_nodes(&self, uids: &[NodeUid]) -> Result<Vec<Node>> {
+        ProtonDriveClient::enumerate_nodes(self, uids).await
+    }
+
+    async fn enumerate_nodes_light(&self, uids: &[NodeUid]) -> Result<Vec<Node>> {
+        ProtonDriveClient::enumerate_nodes_light(self, uids).await
+    }
+
+    async fn enumerate_folder_children_node_uids(
+        &self,
+        folder_uid: &NodeUid,
+    ) -> Result<Vec<NodeUid>> {
+        ProtonDriveClient::enumerate_folder_children_node_uids(self, folder_uid).await
+    }
+
+    async fn enumerate_events(
+        &self,
+        scope: &DriveEventScopeId,
+        cursor: Option<&DriveEventId>,
+    ) -> Result<Vec<DriveEvent>> {
+        ProtonDriveClient::enumerate_events(self, scope, cursor).await
+    }
+
+    async fn invalidate_caches_for_event(&self, event: &DriveEvent) -> Result<()> {
+        ProtonDriveClient::invalidate_caches_for_event(self, event).await
+    }
+
+    async fn create_folder(
+        &self,
+        parent_uid: &NodeUid,
+        name: &str,
+        last_modification_time: Option<i64>,
+    ) -> Result<NodeUid> {
+        ProtonDriveClient::create_folder(self, parent_uid, name, last_modification_time).await
+    }
+
+    async fn upload_file(
+        &self,
+        parent_uid: &NodeUid,
+        name: &str,
+        media_type: &str,
+        contents: &[u8],
+    ) -> Result<NodeUid> {
+        ProtonDriveClient::upload_file(self, parent_uid, name, media_type, contents).await
+    }
+
+    async fn upload_file_from_dyn(
+        &self,
+        parent_uid: &NodeUid,
+        name: &str,
+        media_type: &str,
+        reader: &mut (dyn Read + Send),
+        intended_size: i64,
+        thumbnails: Vec<Thumbnail>,
+        last_modification_time: Option<i64>,
+        aead: bool,
+    ) -> Result<NodeUid> {
+        ProtonDriveClient::upload_file_from(
+            self,
+            parent_uid,
+            name,
+            media_type,
+            reader,
+            intended_size,
+            thumbnails,
+            last_modification_time,
+            aead,
+        )
+        .await
+    }
+
+    async fn upload_file_replacing_draft_from_dyn(
+        &self,
+        parent_uid: &NodeUid,
+        name: &str,
+        media_type: &str,
+        reader: &mut (dyn Read + Send),
+        intended_size: i64,
+        thumbnails: Vec<Thumbnail>,
+        last_modification_time: Option<i64>,
+        aead: bool,
+    ) -> Result<NodeUid> {
+        ProtonDriveClient::upload_file_replacing_draft_from(
+            self,
+            parent_uid,
+            name,
+            media_type,
+            reader,
+            intended_size,
+            thumbnails,
+            last_modification_time,
+            aead,
+        )
+        .await
+    }
+
+    async fn upload_new_revision_from_dyn(
+        &self,
+        file_uid: &NodeUid,
+        reader: &mut (dyn Read + Send),
+        intended_size: i64,
+        thumbnails: Vec<Thumbnail>,
+        last_modification_time: Option<i64>,
+    ) -> Result<()> {
+        ProtonDriveClient::upload_new_revision_from(
+            self,
+            file_uid,
+            reader,
+            intended_size,
+            thumbnails,
+            last_modification_time,
+        )
+        .await
+    }
+
+    async fn open_revision(&self, uid: &NodeUid) -> Result<Arc<dyn RevisionRead>> {
+        let reader = ProtonDriveClient::open_revision(self, uid).await?;
+        Ok(Arc::new(reader))
+    }
+
+    async fn download_file_to_dyn(
+        &self,
+        uid: &NodeUid,
+        output: &mut (dyn Write + Send),
+    ) -> Result<()> {
+        ProtonDriveClient::download_file_to(self, uid, &mut &mut *output).await
+    }
+
+    async fn download_revision_to_dyn(
+        &self,
+        file_uid: &NodeUid,
+        revision_id: &str,
+        writer: &mut (dyn Write + Send),
+    ) -> Result<()> {
+        ProtonDriveClient::download_revision_to(self, file_uid, revision_id, &mut &mut *writer)
+            .await
+    }
+
+    async fn rename_node(
+        &self,
+        uid: &NodeUid,
+        new_name: &str,
+        new_media_type: Option<&str>,
+    ) -> Result<()> {
+        ProtonDriveClient::rename_node(self, uid, new_name, new_media_type).await
+    }
+
+    async fn move_node(&self, uid: &NodeUid, new_parent: &NodeUid) -> Result<()> {
+        ProtonDriveClient::move_node(self, uid, new_parent).await
+    }
+
+    fn move_nodes_streaming<'a>(
+        &'a self,
+        items: Vec<NodeMoveItem>,
+        new_parent: NodeUid,
+    ) -> OutcomeStream<'a> {
+        ProtonDriveClient::move_nodes_streaming(self, items, new_parent).boxed()
+    }
+
+    async fn trash_nodes(&self, uids: &[NodeUid]) -> Result<NodeOutcomes> {
+        ProtonDriveClient::trash_nodes(self, uids).await
+    }
+
+    async fn restore_nodes(&self, uids: &[NodeUid]) -> Result<NodeOutcomes> {
+        ProtonDriveClient::restore_nodes(self, uids).await
+    }
+
+    fn restore_nodes_streaming<'a>(&'a self, uids: &[NodeUid]) -> OutcomeStream<'a> {
+        ProtonDriveClient::restore_nodes_streaming(self, uids).boxed()
+    }
+
+    fn delete_nodes_streaming<'a>(&'a self, uids: &[NodeUid]) -> OutcomeStream<'a> {
+        ProtonDriveClient::delete_nodes_streaming(self, uids).boxed()
+    }
+
+    async fn enumerate_trash_node_uids(&self) -> Result<Vec<NodeUid>> {
+        ProtonDriveClient::enumerate_trash_node_uids(self).await
+    }
+
+    async fn quota(&self) -> Result<Quota> {
+        ProtonDriveClient::quota(self).await
+    }
+}
@@ -9,7 +9,7 @@
 //! through one place (the status, transfers, sync progress) and publishes them
 //! when they differ.

-use std::collections::BTreeSet;
+use std::collections::{BTreeSet, HashMap};
 use std::sync::Arc;
 use std::time::Duration;

@@ -153,13 +153,15 @@ pub(crate) fn transfers_line(items: Vec<TransferItem>, jobs: Vec<JobItem>) -> Op

 /// Watch what changes without a single place to publish it from, and publish it
 /// when it differs from the last look: the status (queue counts, cache use,
-/// online, pause), the transfers snapshot, and the synced folders with their
-/// live progress. Looks only while someone is subscribed.
+/// online, pause), the transfers snapshot, the synced folders with their
+/// live progress, and which nodes have a sync issue. Looks only while someone
+/// is subscribed.
 pub(crate) fn run_event_sampler(core: Core, username: String, mountpoint: std::path::PathBuf) {
    let mut transfers: Option<Arc<str>> = None;
    let mut status: Option<String> = None;
    let mut queue: Option<String> = None;
    let mut locations: Option<String> = None;
+    let mut issues: Option<HashMap<i64, String>> = None;
    let mut tick = 0u32;
    while core.shutdown.sleep(SAMPLE_INTERVAL) {
        if !core.events.has_subscribers() {
@@ -169,6 +171,7 @@ pub(crate) fn run_event_sampler(core: Core, username: String, mountpoint: std::p
            status = None;
            queue = None;
            locations = None;
+            issues = None;
            continue;
        }
        let line = transfers_line(core.transfers.snapshot(), core.jobs_snapshot());
@@ -196,6 +199,15 @@ pub(crate) fn run_event_sampler(core: Core, username: String, mountpoint: std::p
        }
        queue = Some(queue_key);

+        // An issue shows on its node in the file browser: raised, cleared,
+        // landed or discarded, the listing is out of date.
+        if let Ok(now) = core.db.node_issues() {
+            if issues.as_ref().is_some_and(|last| *last != now) {
+                core.events.publish(&[Topic::Files]);
+            }
+            issues = Some(now);
+        }
+
        if let Ok(now) = core.list_locations() {
            let key = serde_json::to_string(&now).unwrap_or_default();
            if locations.as_ref().is_some_and(|last| *last != key) {
@@ -0,0 +1,374 @@
+//! Noticing that the network went away mid-session, and that it came back.
+//!
+//! The mount used to learn it was offline only at startup: a daemon that had
+//! connected once kept `online` true for the rest of its life, so a Wi-Fi drop
+//! turned every create, mkdir, delete and rename into a two-minute wait for an
+//! `EIO`, while the queue that exists for exactly this sat unused. Now any
+//! remote call a handler waits on reports a failure to reach Proton through
+//! [`Core::lost_link`], which flips the mount offline; the handler then takes its
+//! queued path, and the probe thread here flips it back when Proton answers.
+
+use std::future::Future;
+use std::sync::atomic::Ordering;
+use std::time::{Duration, Instant};
+
+use parking_lot::{Condvar, Mutex};
+use proton_drive_rs::proton_sdk::api::ResponseCode;
+use proton_drive_rs::proton_sdk::error::{ProtonApiError, ProtonError};
+use tracing::{debug, info, warn};
+
+use crate::{Core, ONLINE_PROBE_MAX, ONLINE_PROBE_MIN};
+
+/// How long a remote call a FUSE handler is waiting on may take before the link
+/// is treated as down.
+///
+/// The SDK's own budget for one request is four attempts of up to 30 seconds
+/// each, so a dead link held the caller for about two minutes. A metadata call
+/// that has had no answer in 20 seconds is not going to be one the user wants to
+/// keep waiting for; queueing the change is the better answer.
+pub(crate) const INTERACTIVE_CALL_TIMEOUT: Duration = Duration::from_secs(20);
+
+/// How long one probe may wait for an answer. A probe is a single small request,
+/// and a probe stuck in the SDK's retry budget would delay noticing the link is
+/// back by as long as it waits.
+const PROBE_TIMEOUT: Duration = Duration::from_secs(10);
+
+/// First delay between probes after a drop seen mid-session, and the ceiling it
+/// doubles to while the outage is young. A blip should end in seconds, not in
+/// the minutes [`ONLINE_PROBE_MAX`] allows.
+const PROBE_AFTER_DROP: Duration = Duration::from_secs(2);
+const PROBE_YOUNG_MAX: Duration = Duration::from_secs(30);
+/// How long an outage counts as young. Past it the probe backs off to
+/// [`ONLINE_PROBE_MAX`], because a laptop can sit offline for days and each
+/// probe is a real API round trip.
+const YOUNG_OUTAGE: Duration = Duration::from_secs(10 * 60);
+
+/// How often the idle probe thread checks for teardown while the link is up.
+const IDLE_CHECK: Duration = Duration::from_secs(1);
+
+/// The shared half of the online flag: when the link went down, and a condvar
+/// that fires on every change so waiters need not poll.
+#[derive(Default)]
+pub(crate) struct Link {
+    lost_at: Mutex<Option<Instant>>,
+    changed: Condvar,
+    /// Folders listed from the DB alone while offline, to relist once back.
+    pub(crate) stale_listings: Mutex<std::collections::HashSet<u64>>,
+}
+
+/// Whether a failed call failed because Proton could not be reached, rather
+/// than because it answered and refused.
+///
+/// A transport error is the network. So is a request timeout: the SDK reports
+/// Proton's own "try again" codes that way, and [`no_answer`] reports our
+/// deadline that way. Anything else Proton actually said, and says again on a
+/// retry, so it must reach the caller rather than be queued.
+pub(crate) fn is_network_error(e: &ProtonError) -> bool {
+    match e {
+        ProtonError::Transport(_) => true,
+        ProtonError::Api(api) => {
+            matches!(
+                api.code,
+                ResponseCode::RequestTimeout | ResponseCode::Timeout
+            )
+        }
+        _ => false,
+    }
+}
+
+/// The error a call reports when it runs past `after` without an answer.
+pub(crate) fn no_answer(after: Duration) -> ProtonError {
+    ProtonError::Api(ProtonApiError {
+        code: ResponseCode::RequestTimeout,
+        http_status: 408,
+        message: format!("no answer within {}s", after.as_secs()),
+        details: None,
+    })
+}
+
+/// The slowest upload rate an upload's deadline allows for, past the
+/// metadata budget it starts with. Far below any link that works, so only a
+/// transfer that has stopped moving runs into it.
+const SLOWEST_UPLOAD: u64 = 32 * 1024;
+
+/// How long an upload of `len` bytes may take before the link is treated as
+/// down: the budget of a metadata call, plus the bytes at [`SLOWEST_UPLOAD`].
+pub(crate) fn upload_deadline(len: u64) -> Duration {
+    INTERACTIVE_CALL_TIMEOUT + Duration::from_secs(len / SLOWEST_UPLOAD)
+}
+
+/// Run a remote call, giving up after [`INTERACTIVE_CALL_TIMEOUT`].
+pub(crate) async fn bounded<T>(
+    call: impl Future<Output = Result<T, ProtonError>>,
+) -> Result<T, ProtonError> {
+    bounded_by(INTERACTIVE_CALL_TIMEOUT, call).await
+}
+
+/// Run a remote call, giving up after `limit`.
+pub(crate) async fn bounded_by<T>(
+    limit: Duration,
+    call: impl Future<Output = Result<T, ProtonError>>,
+) -> Result<T, ProtonError> {
+    match tokio::time::timeout(limit, call).await {
+        Ok(result) => result,
+        Err(_) => Err(no_answer(limit)),
+    }
+}
+
+/// The next delay between probes, given the current one and how long the
+/// outage has lasted.
+fn next_probe_delay(delay: Duration, outage: Duration) -> Duration {
+    let cap = if outage < YOUNG_OUTAGE {
+        PROBE_YOUNG_MAX
+    } else {
+        ONLINE_PROBE_MAX
+    };
+    (delay * 2).min(cap)
+}
+
+impl Core {
+    /// Whether the mount currently believes Proton is reachable.
+    pub(crate) fn is_online(&self) -> bool {
+        self.online.load(Ordering::Relaxed)
+    }
+
+    /// Whether a namespace change through the mount goes to Drive inside the
+    /// syscall. Only with [`AppConfig::local_first`] off, and only online;
+    /// otherwise it is queued and the drain sends it.
+    ///
+    /// [`AppConfig::local_first`]: pdfs_core::config::AppConfig::local_first
+    pub(crate) fn sends_inline(&self) -> bool {
+        !self.local_first && self.is_online()
+    }
+
+    /// Run a remote call a caller is waiting on, giving up after
+    /// [`INTERACTIVE_CALL_TIMEOUT`]. The timer is built inside the runtime: a
+    /// FUSE worker has no reactor of its own.
+    pub(crate) fn block_on_bounded<T>(
+        &self,
+        call: impl Future<Output = Result<T, ProtonError>>,
+    ) -> Result<T, ProtonError> {
+        self.rt.block_on(bounded(call))
+    }
+
+    /// Run a remote call, giving up after `limit`: an upload, whose budget
+    /// grows with its size ([`upload_deadline`]).
+    pub(crate) fn block_on_within<T>(
+        &self,
+        limit: Duration,
+        call: impl Future<Output = Result<T, ProtonError>>,
+    ) -> Result<T, ProtonError> {
+        self.rt.block_on(bounded_by(limit, call))
+    }
+
+    /// Report a failed remote call. Returns whether it failed for want of a
+    /// network, in which case the mount is now offline and the caller should
+    /// take its queued path instead of failing.
+    pub(crate) fn lost_link(&self, e: &ProtonError, what: &str) -> bool {
+        if !is_network_error(e) {
+            return false;
+        }
+        self.mark_offline(what, e);
+        true
+    }
+
+    /// Flip the mount offline and wake the probe. Only the first caller of an
+    /// outage logs it; the rest are the same outage.
+    pub(crate) fn mark_offline(&self, what: &str, error: &dyn std::fmt::Display) {
+        let mut lost_at = self.link.lost_at.lock();
+        if self.online.swap(false, Ordering::Relaxed) {
+            *lost_at = Some(Instant::now());
+            warn!(during = what, %error,
+                  "lost the connection to Proton; queueing changes until it returns");
+            self.link.changed.notify_all();
+        }
+    }
+
+    /// Flip the mount back online, wake everything waiting for it, and let the
+    /// queue drain.
+    fn mark_online(&self) {
+        {
+            let mut lost_at = self.link.lost_at.lock();
+            self.online.store(true, Ordering::Relaxed);
+            match lost_at.take() {
+                Some(since) => {
+                    info!(
+                        offline_secs = since.elapsed().as_secs(),
+                        "connection to Proton is back"
+                    )
+                }
+                None => info!("back online"),
+            }
+            self.link.changed.notify_all();
+        }
+        self.relist_offline_listings();
+        // Anything written while offline is queued and waiting on exactly this,
+        // including ops that failed on the way down and are sitting out a
+        // backoff sized for a server that keeps refusing.
+        if let Err(e) = self.db.retry_failed_ops_now(crate::now_millis()) {
+            warn!(error = %e, "moving backed-off ops up after a reconnect failed");
+        }
+        self.wake_drain();
+    }
+
+    /// Wait up to `budget` for the link to come back. Returns whether it is up.
+    pub(crate) fn wait_online(&self, budget: Duration) -> bool {
+        let deadline = Instant::now() + budget;
+        let mut lost_at = self.link.lost_at.lock();
+        while !self.is_online() {
+            if self.shutdown.is_stopping()
+                || self
+                    .link
+                    .changed
+                    .wait_until(&mut lost_at, deadline)
+                    .timed_out()
+            {
+                return self.is_online();
+            }
+        }
+        true
+    }
+
+    /// Wait out `interval` before a background poll of Proton, and while the
+    /// link is down, until it is back. Returns as soon as it comes back, so the
+    /// poll catches up on what changed during the outage at once instead of
+    /// one interval later. A poll into a dead link would only wait out the
+    /// SDK's retries and fail.
+    pub(crate) async fn next_poll(&self, interval: Duration) {
+        let due = Instant::now() + interval;
+        let mut was_offline = false;
+        loop {
+            if !self.is_online() {
+                was_offline = true;
+            } else if was_offline || Instant::now() >= due {
+                return;
+            }
+            tokio::time::sleep(IDLE_CHECK).await;
+        }
+    }
+
+    /// Watch the link for the life of the mount: sleep while it is up, and
+    /// probe it back while it is down.
+    ///
+    /// A mount that started from the cache is down from the first moment; one
+    /// that started online goes down when [`Core::mark_offline`] says so.
+    pub(crate) fn run_online_probe(&self) {
+        // Only an offline start never had a chance to repair its share id.
+        let mut repair_share_id = !self.is_online();
+        loop {
+            {
+                let mut lost_at = self.link.lost_at.lock();
+                while self.is_online() {
+                    if self.shutdown.is_stopping() {
+                        return;
+                    }
+                    self.link.changed.wait_for(&mut lost_at, IDLE_CHECK);
+                }
+            }
+            if !self.probe_until_online() {
+                return;
+            }
+            if std::mem::take(&mut repair_share_id) {
+                self.repair_primary_share_id(&self.primary_root_uid);
+            }
+        }
+    }
+
+    /// Probe until Proton answers, then flip the mount online. Returns `false`
+    /// if the daemon is stopping.
+    fn probe_until_online(&self) -> bool {
+        let started = self.link.lost_at.lock().unwrap_or_else(Instant::now);
+        let mut delay = if started.elapsed() < YOUNG_OUTAGE {
+            PROBE_AFTER_DROP
+        } else {
+            ONLINE_PROBE_MIN
+        };
+        loop {
+            if !self.shutdown.sleep(delay) {
+                return false;
+            }
+            let probe = self.rt.block_on(async {
+                match tokio::time::timeout(PROBE_TIMEOUT, self.drive.get_my_files_folder()).await {
+                    Ok(result) => result,
+                    Err(_) => Err(no_answer(PROBE_TIMEOUT)),
+                }
+            });
+            match probe {
+                Ok(root) => {
+                    {
+                        let root_ino = self.root_ino();
+                        let mut st = self.state();
+                        if let Some(e) = st.entries.get_mut(&root_ino) {
+                            e.node = root.clone();
+                        }
+                    }
+                    if let Err(e) = self.db.upsert_node(&root) {
+                        warn!(error = %e, "refresh root after reconnect failed");
+                    }
+                    self.mark_online();
+                    return true;
+                }
+                Err(e) => {
+                    debug!(error = %e, ?delay, "online probe failed; still offline");
+                    delay = next_probe_delay(delay, started.elapsed());
+                }
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn api(code: ResponseCode) -> ProtonError {
+        ProtonError::Api(ProtonApiError {
+            code,
+            http_status: 422,
+            message: String::new(),
+            details: None,
+        })
+    }
+
+    #[test]
+    fn only_an_unanswered_call_counts_as_a_lost_link() {
+        assert!(is_network_error(&no_answer(INTERACTIVE_CALL_TIMEOUT)));
+        assert!(is_network_error(&api(ResponseCode::Timeout)));
+        assert!(!is_network_error(&api(ResponseCode::AlreadyExists)));
+        assert!(!is_network_error(&api(ResponseCode::InvalidRequirements)));
+        assert!(!is_network_error(&ProtonError::invalid_operation("bug")));
+    }
+
+    #[test]
+    fn an_upload_gets_longer_the_bigger_it_is() {
+        assert_eq!(upload_deadline(0), INTERACTIVE_CALL_TIMEOUT);
+        assert_eq!(
+            upload_deadline(1 << 30),
+            INTERACTIVE_CALL_TIMEOUT + Duration::from_secs(32_768)
+        );
+    }
+
+    #[test]
+    fn a_call_past_its_deadline_reads_as_a_lost_link() {
+        let rt = tokio::runtime::Builder::new_current_thread()
+            .enable_time()
+            .build()
+            .unwrap();
+        let limit = Duration::from_millis(20);
+        let result: Result<(), _> = rt.block_on(bounded_by(limit, std::future::pending()));
+        assert!(result.is_err_and(|e| is_network_error(&e)));
+    }
+
+    #[test]
+    fn a_young_outage_is_probed_often_and_an_old_one_rarely() {
+        let young = Duration::from_secs(60);
+        let old = YOUNG_OUTAGE + Duration::from_secs(1);
+        assert_eq!(
+            next_probe_delay(PROBE_AFTER_DROP, young),
+            2 * PROBE_AFTER_DROP
+        );
+        assert_eq!(next_probe_delay(PROBE_YOUNG_MAX, young), PROBE_YOUNG_MAX);
+        assert_eq!(next_probe_delay(PROBE_YOUNG_MAX, old), 2 * PROBE_YOUNG_MAX);
+        assert_eq!(next_probe_delay(ONLINE_PROBE_MAX, old), ONLINE_PROBE_MAX);
+    }
+}
@@ -193,7 +193,7 @@ pub(super) fn clear_stale_mount(mountpoint: &Path) {
 }

 /// `sync_state` key holding the uid of the My Files root, so a later run can
-/// recover it from `nodes` without the API (offline.md Phase 1).
+/// recover it from `nodes` without the API.
 const ROOT_UID_KEY: &str = "root_uid";

 /// The My Files root, and whether we got it from the API (`true`) or from the
@@ -207,11 +207,11 @@ const ROOT_UID_KEY: &str = "root_uid";
 /// means an empty tree, and mounting that would show the user an empty Drive
 /// rather than an honest error.
 fn fetch_or_recall_root(
-    client: &ProtonDriveClient,
+    drive: &dyn DriveApi,
    rt: &tokio::runtime::Handle,
    db: &Db,
 ) -> std::io::Result<(Node, bool)> {
-    let err = match rt.block_on(client.get_my_files_folder()) {
+    let err = match rt.block_on(drive.get_my_files_folder()) {
        Ok(root) => {
            if let Err(e) = db.set_state_str(ROOT_UID_KEY, &root.uid.to_string()) {
                warn!(error = %e, "persist root uid failed");
@@ -244,6 +244,9 @@ pub struct MountOptions {
    /// Upload and download caps in bytes per second (`0` = no cap).
    pub upload_limit: u64,
    pub download_limit: u64,
+    /// Namespace changes through the mount are queued, not sent in the
+    /// syscall. See [`pdfs_core::config::AppConfig::local_first`].
+    pub local_first: bool,
 }

 /// Spawn one FUSE session rooted at an arbitrary remote node.
@@ -276,13 +279,14 @@ pub(super) fn spawn_session(
    info!(mountpoint = %mountpoint.display(), "mounting Proton Drive location");
    let fs = ProtonFs::new(core.clone(), root);
    if core.primary {
-        // Only My Files rehydrates the daemon-wide node cache. A secondary
-        // inode space is rooted at one device subtree and must not import every
-        // unrelated persisted node.
+        // Only My Files rehydrates the daemon-wide node cache, once. A
+        // secondary mount shares the tree it fills.
        core.hydrate();
    }
    let session = Session::new(fs, mountpoint, &config)?.spawn()?;
-    let _ = core.notifier.set(session.notifier());
+    let _ = core
+        .notifier
+        .set(KernelChannel::new(session.notifier(), core.root_ino()));
    core.session_live.store(true, Ordering::Release);
    Ok(session)
 }
@@ -339,17 +343,57 @@ pub fn mount(
    control_socket: &Path,
    db: Arc<Db>,
    options: MountOptions,
+) -> std::io::Result<MountOutcome> {
+    let drive = Arc::new(client.clone());
+    mount_with(
+        client,
+        drive,
+        rt,
+        mountpoint,
+        cache,
+        control_socket,
+        db,
+        options,
+        Host::Daemon,
+    )
+}
+
+/// What a mount runs in.
+pub(crate) enum Host {
+    /// The daemon: stopped by SIGTERM or SIGINT, and indexing the user's home
+    /// for the launcher prompt.
+    Daemon,
+    /// One of several simulated daemons in a test process (`sim`): stopped by
+    /// a message on this channel, and with no home to index.
+    #[cfg(test)]
+    Simulation(std::sync::mpsc::Receiver<()>),
+}
+
+/// [`mount`], reaching Drive through `drive` and hosted by `host`; `client`
+/// serves only what [`DriveApi`] does not cover.
+#[allow(clippy::too_many_arguments)]
+pub(crate) fn mount_with(
+    client: ProtonDriveClient,
+    drive: Arc<dyn DriveApi>,
+    rt: tokio::runtime::Handle,
+    mountpoint: &Path,
+    cache: ContentCache,
+    control_socket: &Path,
+    db: Arc<Db>,
+    options: MountOptions,
+    host: Host,
 ) -> std::io::Result<MountOutcome> {
    let MountOptions {
        username,
        sweep_mode,
        upload_limit,
        download_limit,
+        local_first,
    } = options;
    // Start the uptime clock here rather than at the first `pdfs diagnostics`,
    // so the age it reports is the daemon's own.
    super::diagnostics::start_clock();
-    let (root, online) = fetch_or_recall_root(&client, &rt, &db)?;
+    let (root, online) = fetch_or_recall_root(drive.as_ref(), &rt, &db)?;
    let scope = root.tree_event_scope_id();
    db.mount_upsert_my_files(&mountpoint.to_string_lossy(), &root.uid.to_string(), None)
        .map_err(|error| std::io::Error::other(format!("project My Files mount: {error}")))?;
@@ -357,19 +401,21 @@ pub fn mount(
        .all_share_access()
        .map_err(|error| std::io::Error::other(format!("load shared access: {error}")))?;

-    // The folder-sync engine (devices.md Phase 2) runs on its own thread and is
+    // The folder-sync engine runs on its own thread and is
    // nudged over this channel; the sender lives in Core so control-socket
    // handlers can trigger reconciles.
    let (sync_tx, sync_rx) = std::sync::mpsc::channel::<sync::SyncMsg>();

    let paused_until = pause::load_paused_until(&db);
    let core = Core {
-        client: client.clone(),
+        drive,
+        client,
        rt: rt.clone(),
        maintenance: Arc::new(Mutex::new(Default::default())),
        primary_root_uid: root.uid.clone(),
        primary: true,
-        state: Arc::new(Mutex::new(State::new(db.clone(), share_access, 2))),
+        state: Arc::new(Mutex::new(State::new(db.clone(), share_access))),
+        root: Arc::new(OnceLock::new()),
        cache: Arc::new(cache),
        readers: Arc::new(Mutex::new(HashMap::new())),
        block_ring: Arc::new(Mutex::new(BlockRing::default())),
@@ -383,13 +429,19 @@ pub fn mount(
        shared_generation: Arc::new(AtomicU64::new(0)),
        shared_refresh_deadlines: Arc::new(Mutex::new(SharedRefreshDeadlines::default())),
        online: Arc::new(AtomicBool::new(online)),
+        link: Arc::new(Default::default()),
        sync_paused_until: Arc::new(AtomicI64::new(paused_until)),
        pending: Arc::new(Mutex::new(HashMap::new())),
        hidden: Arc::new(Mutex::new(HashSet::new())),
+        creating: Arc::new(Mutex::new(HashMap::new())),
+        sealed_unread: Arc::new(Mutex::new(HashMap::new())),
+        landed: Arc::new(Mutex::new(HashMap::new())),
+        unadopted: Arc::new(Mutex::new(HashMap::new())),
        drain_wake: Arc::new((Mutex::new(false), Condvar::new())),
        shutdown: Arc::new(crate::shutdown::Shutdown::default()),
        upload_times: Arc::new(Mutex::new(HashMap::new())),
        upload_cancel: Arc::new(Mutex::new(HashMap::new())),
+        landing_uploads: Arc::new(AtomicU64::new(0)),
        timeline_refreshing: Arc::new(AtomicBool::new(false)),
        timeline_progress: Arc::new(Mutex::new(None)),
        similar_hashing: Arc::new(AtomicBool::new(false)),
@@ -398,7 +450,7 @@ pub fn mount(
        trash_progress: Arc::new(tokio::sync::Notify::new()),
        conflict_notified: Arc::new(Mutex::new(HashSet::new())),
        sweep_mode,
-        own_sealed_revs: Arc::new(Mutex::new(HashMap::new())),
+        local_first,
        self_changes: Arc::new(Mutex::new(HashMap::new())),
        thumb_gen: Arc::new(Mutex::new(HashSet::new())),
        thumb_gen_budget: Arc::new(tokio::sync::Semaphore::new(
@@ -411,6 +463,7 @@ pub fn mount(
        thumbnail_build_cancel: Arc::new(tokio::sync::Notify::new()),
        thumbnail_misses: Arc::new(Mutex::new(Default::default())),
        quota: Arc::new(Mutex::new(None)),
+        quota_refreshing: Arc::new(AtomicBool::new(false)),
        size_upgrades: Arc::new(Mutex::new(HashMap::new())),
        size_waiters: Arc::new(Default::default()),
        notifier: Arc::new(OnceLock::new()),
@@ -425,7 +478,7 @@ pub fn mount(
        states: Arc::new(StateRegistry::default()),
    };
    // Before anything can queue work against it: the drain thread below reaches
-    // every mount's inode space through this registry, not through `core.state`.
+    // every mount's session through this registry.
    core.register_state(mountpoint);
    core.transfers.set_limits(upload_limit, download_limit);

@@ -448,7 +501,7 @@ pub fn mount(
    // Every long-lived thread started from here on is kept in `workers` and
    // joined at the end of this function. Leaving them running turned an
    // in-process remount into a second generation of drain workers, sync engines
-    // and sweeps all operating on a mount that no longer exists (bugs.md B44).
+    // and sweeps all operating on a mount that no longer exists (`docs/BUGS.md` B44).
    let mut workers: Vec<std::thread::JoinHandle<()>> = Vec::new();
    for worker in 0..DRAIN_WORKERS {
        let core = core.clone();
@@ -484,9 +537,10 @@ pub fn mount(
        );
    }

-    // Mounted from the cache: watch for the network coming back so the mount can
-    // stop being read-only-ish without the user restarting the daemon.
-    if !online {
+    // Watch the link for the life of the mount: a mount from the cache waits for
+    // the network to come back, and an online one can lose it at any moment and
+    // must notice it coming back just the same.
+    {
        let core = core.clone();
        workers.push(
            std::thread::Builder::new()
@@ -497,7 +551,7 @@ pub fn mount(

    // Keep the launcher prompt's "This computer" index fresh. Its own thread:
    // the walk is I/O-heavy and must never sit in front of a FUSE callback.
-    {
+    if matches!(host, Host::Daemon) {
        let db = core.db.clone();
        let indexing = core.indexing.clone();
        let transfers = core.transfers.clone();
@@ -621,11 +675,13 @@ pub fn mount(
            }
        }
    };
-    rt.spawn(run_event_sync(client, scope, core.clone()));
+    rt.spawn(run_event_sync(core.drive.clone(), scope, core.clone()));
    // The photos volume has its own event stream; without it the gallery only
    // learns about a phone-side deletion when the timeline goes stale.
    rt.spawn(run_photos_event_sync(core.clone()));
-    if online {
+    // Not in a simulation: `client` there reaches no API, and the thread, still
+    // waiting on it after the stop, held the database a test opens next.
+    if online && matches!(host, Host::Daemon) {
        let repair_core = core.clone();
        let root_uid = core.primary_root_uid.clone();
        if let Err(error) = std::thread::Builder::new()
@@ -640,30 +696,11 @@ pub fn mount(
    // are delivered onto the async runtime; bridge them onto a sync channel so
    // the loop below can react without blocking a worker thread. A bounded
    // channel of 1 is enough — we only need to know that *a* stop arrived.
-    let (sig_tx, sig_rx) = std::sync::mpsc::sync_channel::<()>(1);
-    rt.spawn(async move {
-        let mut sigterm =
-            match tokio::signal::unix::signal(tokio::signal::unix::SignalKind::terminate()) {
-                Ok(s) => s,
-                Err(e) => {
-                    warn!(error = %e, "install SIGTERM handler failed");
-                    return;
-                }
-            };
-        let mut sigint =
-            match tokio::signal::unix::signal(tokio::signal::unix::SignalKind::interrupt()) {
-                Ok(s) => s,
-                Err(e) => {
-                    warn!(error = %e, "install SIGINT handler failed");
-                    return;
-                }
-            };
-        tokio::select! {
-            _ = sigterm.recv() => info!("received SIGTERM"),
-            _ = sigint.recv() => info!("received SIGINT"),
-        }
-        let _ = sig_tx.try_send(());
-    });
+    let sig_rx = match host {
+        Host::Daemon => signal_stop(&rt),
+        #[cfg(test)]
+        Host::Simulation(rx) => rx,
+    };

    // Wait for whichever happens first: a stop signal (→ we unmount ourselves
    // via the lazy MNT_DETACH path, clean even mid-download), or the kernel
@@ -701,7 +738,7 @@ pub fn mount(
    };

    // Unmount every on-demand sync folder too, or the kernel mounts linger as
-    // stale and the next start fails with EBUSY (devices.md Phase 3).
+    // stale and the next start fails with EBUSY.
    if let Some(worker) = restore_worker
        && worker.join().is_err()
    {
@@ -713,6 +750,7 @@ pub fn mount(
            warn!(id, error = %e, "unmount on-demand folder failed");
        }
    }
+    core.queue_unreleased_writes();

    // Last, because the workers may legitimately be finishing an upload, and
    // nothing they can still do is harmful once the mounts are down.
@@ -720,9 +758,39 @@ pub fn mount(
    Ok(outcome)
 }

-/// How long teardown waits for the FUSE worker pool before proceeding without
-/// it. Long enough for an in-flight block to finish, short enough that
-/// `systemctl --user stop` still returns inside `TimeoutStopSec`.
+/// A channel that receives once SIGTERM or SIGINT arrives.
+fn signal_stop(rt: &tokio::runtime::Handle) -> std::sync::mpsc::Receiver<()> {
+    let (sig_tx, sig_rx) = std::sync::mpsc::sync_channel::<()>(1);
+    rt.spawn(async move {
+        let mut sigterm =
+            match tokio::signal::unix::signal(tokio::signal::unix::SignalKind::terminate()) {
+                Ok(s) => s,
+                Err(e) => {
+                    warn!(error = %e, "install SIGTERM handler failed");
+                    return;
+                }
+            };
+        let mut sigint =
+            match tokio::signal::unix::signal(tokio::signal::unix::SignalKind::interrupt()) {
+                Ok(s) => s,
+                Err(e) => {
+                    warn!(error = %e, "install SIGINT handler failed");
+                    return;
+                }
+            };
+        tokio::select! {
+            _ = sigterm.recv() => info!("received SIGTERM"),
+            _ = sigint.recv() => info!("received SIGINT"),
+        }
+        let _ = sig_tx.try_send(());
+    });
+    sig_rx
+}
+
+/// How long teardown waits for the background workers and then the FUSE worker
+/// pool before proceeding without them. Long enough for an in-flight block to
+/// finish, short enough that `systemctl --user stop` still returns inside
+/// `TimeoutStopSec`.
 const WORKER_JOIN_DEADLINE: Duration = Duration::from_secs(10);

 /// Signal every background loop, wake the ones that are blocked, and join them.
@@ -730,14 +798,15 @@ const WORKER_JOIN_DEADLINE: Duration = Duration::from_secs(10);
 /// The mount used to return with its drain workers, sync engine, sweep, online
 /// probe, indexer and control listener all still running on `Core` clones. The
 /// process usually exited straight afterwards and hid it; an in-process remount
-/// did not, and started a second full set on top of the first (bugs.md B44).
+/// did not, and started a second full set on top of the first (`docs/BUGS.md` B44).
 ///
 /// Two of the waits need waking rather than merely flagging: the drain workers
 /// block on their own condvar (`wake_drain`), and the control listener blocks
 /// inside `accept`, which only returns when a connection arrives — so it gets
 /// one, from us, after the flag is already set. A join that takes a while is
 /// expected and correct: a worker part-way through an upload finishes it rather
-/// than abandoning the user's bytes mid-flight.
+/// than abandoning the user's bytes mid-flight. Up to [`WORKER_JOIN_DEADLINE`]:
+/// past it, systemd kills the daemon anyway, and a queued op is sent again.
 fn stop_workers(core: &Core, control_socket: &Path, workers: Vec<std::thread::JoinHandle<()>>) {
    // Say so before the joins: a teardown that takes a while must not be read as
    // a missed watchdog ping and turned into a kill.
@@ -751,25 +820,71 @@ fn stop_workers(core: &Core, control_socket: &Path, workers: Vec<std::thread::Jo
    // unlink cannot put it back to sleep.
    let _ = std::os::unix::net::UnixStream::connect(control_socket);
    let _ = std::fs::remove_file(control_socket);
-    for worker in workers {
-        if worker.join().is_err() {
-            warn!("a background worker panicked before shutdown");
-        }
+    let deadline = Instant::now() + WORKER_JOIN_DEADLINE;
+    let running = join_until(workers, deadline);
+    if !running.is_empty() {
+        warn!(
+            running = running.join(","),
+            "background workers did not finish in time; shutting down around them"
+        );
    }
    // The FUSE worker pool last, and *before* the caller drops the tokio
    // runtime: a worker still inside a job when the runtime goes away panics on
    // its next timer with "A Tokio 1.x context was found, but it is being
    // shutdown" (seen 2026-09-18 09:58:35). Bounded, so a worker wedged on the
    // network cannot hold the stop the user asked for.
-    core.workers.stop_and_join(WORKER_JOIN_DEADLINE);
+    core.workers
+        .stop_and_join(deadline.saturating_duration_since(Instant::now()));
    debug!("background workers stopped");
 }

+/// Join `workers` until `deadline`, and name the ones still running then.
+///
+/// A stop used to wait for each one however long it took. The sync engine's
+/// mirror pass waits on Drive with no deadline, and a stop that waited for it
+/// was killed by systemd (`docs/BUGS.md` B165).
+fn join_until(workers: Vec<std::thread::JoinHandle<()>>, deadline: Instant) -> Vec<String> {
+    let mut running = Vec::new();
+    for worker in workers {
+        while !worker.is_finished() && Instant::now() < deadline {
+            std::thread::sleep(Duration::from_millis(10));
+        }
+        if !worker.is_finished() {
+            running.push(worker.thread().name().unwrap_or("unnamed").to_string());
+        } else if worker.join().is_err() {
+            warn!("a background worker panicked before shutdown");
+        }
+    }
+    running
+}
+
 #[cfg(test)]
 mod tests {
    use std::sync::atomic::{AtomicBool, Ordering};
+    use std::time::{Duration, Instant};

-    use super::{SecondaryInsertRejection, SecondaryMountRegistry, teardown_session};
+    use super::{SecondaryInsertRejection, SecondaryMountRegistry, join_until, teardown_session};
+
+    #[test]
+    fn a_stop_names_the_workers_still_running_at_its_deadline() {
+        let (release, wait) = std::sync::mpsc::channel::<()>();
+        let done = std::thread::Builder::new()
+            .name("done".into())
+            .spawn(|| {})
+            .unwrap();
+        let stuck = std::thread::Builder::new()
+            .name("stuck".into())
+            .spawn(move || {
+                let _ = wait.recv();
+            })
+            .unwrap();
+        let running = join_until(
+            vec![done, stuck],
+            Instant::now() + Duration::from_millis(100),
+        );
+        assert_eq!(running, ["stuck"]);
+        drop(release);
+    }

    #[test]
    fn session_is_unroutable_before_teardown_starts() {
@@ -1038,7 +1038,7 @@ impl Core {
        }
        let outcomes = self
            .rt
-            .block_on(self.client.trash_nodes(uids))
+            .block_on(self.drive.trash_nodes(uids))
            .map_err(|e| CoreError::from_api(&e, "trash"))?;
        let (trashed, failed) = pdfs_core::batch::split(outcomes);

@@ -1,5 +1,5 @@
 //! Reading and writing this machine's `profile.json` in its device root, and
-//! the restore that rebuilds a machine from one (features.md 5.2 and 5.3).
+//! the restore that rebuilds a machine from one.
 //!
 //! The document itself is defined in [`pdfs_core::profile`]; this is the half
 //! that talks to Drive. Saving is best-effort and never blocks a user action:
@@ -101,7 +101,7 @@ impl Core {
        match existing {
            Some(uid) => self
                .rt
-                .block_on(self.client.upload_new_revision_from(
+                .block_on(self.drive.upload_new_revision_from(
                    &uid,
                    Cursor::new(bytes),
                    len,
@@ -112,7 +112,7 @@ impl Core {
                .map_err(|e| CoreError::from_api(&e, "upload profile revision"))?,
            None => {
                self.rt
-                    .block_on(self.client.upload_file_replacing_draft_from(
+                    .block_on(self.drive.upload_file_replacing_draft_from(
                        &dir_uid,
                        PROFILE_FILE_NAME,
                        "application/json",
@@ -182,14 +182,14 @@ impl Core {
    ) -> CoreResult<Option<NodeUid>> {
        let uids = self
            .rt
-            .block_on(self.client.enumerate_folder_children_node_uids(parent_uid))
+            .block_on(self.drive.enumerate_folder_children_node_uids(parent_uid))
            .map_err(|e| CoreError::from_api(&e, "list device root"))?;
        if uids.is_empty() {
            return Ok(None);
        }
        let nodes = self
            .rt
-            .block_on(self.client.enumerate_nodes(&uids))
+            .block_on(self.drive.enumerate_nodes(&uids))
            .map_err(|e| CoreError::from_api(&e, "resolve device root children"))?;
        Ok(nodes
            .into_iter()
@@ -210,7 +210,7 @@ impl Core {
        let uid = self
            .rt
            .block_on(
-                self.client
+                self.drive
                    .create_folder(root_uid, PROFILE_DIR_NAME, Some(now_secs())),
            )
            .map_err(|e| CoreError::from_api(&e, "create profile folder"))?;
@@ -241,12 +241,12 @@ impl Core {
        };
        let mut buf: Vec<u8> = Vec::new();
        self.rt
-            .block_on(self.client.download_file_to(&uid, &mut buf))
+            .block_on(self.drive.download_file_to(&uid, &mut buf))
            .map_err(|e| CoreError::from_api(&e, "download profile"))?;
        Profile::parse(&buf).map(Some).map_err(CoreError::invalid)
    }

-    // ---- restore (features.md 5.2) ----------------------------------------
+    // ---- restore ----------------------------------------

    /// The folders under a device that could be synced here, each carrying a
    /// proposed local path. `device` names another registered device by uid;
@@ -277,13 +277,13 @@ impl Core {

        let uids = self
            .rt
-            .block_on(self.client.enumerate_folder_children_node_uids(&root_uid))
+            .block_on(self.drive.enumerate_folder_children_node_uids(&root_uid))
            .map_err(|e| CoreError::from_api(&e, "list device root"))?;
        let nodes = if uids.is_empty() {
            Vec::new()
        } else {
            self.rt
-                .block_on(self.client.enumerate_nodes(&uids))
+                .block_on(self.drive.enumerate_nodes(&uids))
                .map_err(|e| CoreError::from_api(&e, "resolve device root children"))?
        };

@@ -1,12 +1,16 @@
 //! The user's view of the pending-op queue: what has not reached the remote
 //! yet, why, and a way to stop waiting out a backoff.
 //!
-//! Read-only apart from "retry now", which only moves a row's next-attempt time.
-//! Nothing here drops a queued op: its staged blob is the only copy of the
-//! user's write (see `docs/RECOVERY.md`).
+//! Read-only apart from "retry now", which only moves a row's next-attempt time,
+//! "export", which copies a staged blob out, and "discard". Only a discard the
+//! user asks for drops a queued op: its staged blob is the only copy of the
+//! user's write (see `docs/RECOVERY.md`), so it is the user's call, made after
+//! an export or for a change with no content.

 use super::*;
-use pdfs_core::control::PendingOpInfo;
+use std::io::Write;
+
+use pdfs_core::control::{PendingOpInfo, SyncIssue};
 use pdfs_core::db::{FAILING_ATTEMPTS, PARK_UNTIL};

 impl Core {
@@ -16,10 +20,15 @@ impl Core {
            .db
            .pending_ops()
            .map_err(|e| CoreError::internal(format!("listing the queue: {e}")))?;
+        let issues = self
+            .db
+            .op_issues()
+            .map_err(|e| CoreError::internal(format!("listing sync issues: {e}")))?;
        Ok(ops
            .into_iter()
            .map(|op| {
                let parked = op.next_attempt_at >= PARK_UNTIL;
+                let exportable = exportable(&op).is_some();
                let path = self
                    .db
                    .node_path(&op.uid)
@@ -37,7 +46,9 @@ impl Core {
                    queued_at: op.created_at / 1000,
                    next_attempt_at: (!parked).then_some(op.next_attempt_at / 1000),
                    parked,
-                    failing: op.attempts >= FAILING_ATTEMPTS,
+                    failing: op.attempts >= FAILING_ATTEMPTS || issues.contains_key(&op.id),
+                    issue: issues.get(&op.id).map(|issue| SyncIssue::parse(issue)),
+                    exportable,
                }
            })
            .collect())
@@ -57,4 +68,235 @@ impl Core {
        }
        Ok(moved)
    }
+
+    /// Copy the content of queued op `id` to `dest`, which must not exist yet.
+    /// The op stays queued. Returns the bytes written.
+    pub(crate) fn export_pending_op(&self, id: i64, dest: &Path) -> CoreResult<u64> {
+        if !dest.is_absolute() {
+            return Err(CoreError::invalid(format!(
+                "destination must be an absolute path: {}",
+                dest.display()
+            )));
+        }
+        let ops = self
+            .db
+            .pending_ops()
+            .map_err(|e| CoreError::internal(format!("listing the queue: {e}")))?;
+        let op = ops
+            .iter()
+            .find(|op| op.id == id)
+            .ok_or_else(|| CoreError::not_found(format!("no queued change {id}")))?;
+        let blob = exportable(op).ok_or_else(|| {
+            CoreError::invalid(format!("queued change {id} carries no file content"))
+        })?;
+        let written = copy_to_new_file(blob, dest)?;
+        info!(id, dest = %dest.display(), written, "exported a queued change's content");
+        Ok(written)
+    }
+
+    /// Drop queued op `id` and undo the local change it stood for. Returns the
+    /// node's path.
+    ///
+    /// A node only made here goes, as if it had been deleted before it was
+    /// sent. A node Drive has goes back to what Drive has: every change queued
+    /// on it goes, since each was made on top of the one before. What is queued
+    /// below it stays.
+    pub(crate) fn discard_pending_op(&self, id: i64) -> CoreResult<String> {
+        let ops = self
+            .db
+            .pending_ops()
+            .map_err(|e| CoreError::internal(format!("listing the queue: {e}")))?;
+        let op = ops
+            .into_iter()
+            .find(|op| op.id == id)
+            .ok_or_else(|| CoreError::not_found(format!("no queued change {id}")))?;
+        let uid = parse_node_uid(&op.uid)
+            .ok_or_else(|| CoreError::internal(format!("queued change {id} names {}", op.uid)))?;
+        let path = self
+            .db
+            .node_path(&op.uid)
+            .ok()
+            .flatten()
+            .filter(|path| !path.is_empty())
+            .or(op.name)
+            .unwrap_or_else(|| op.uid.clone());
+        if self.is_open_anywhere(&uid) {
+            return Err(CoreError::conflict(format!(
+                "{path} is open; close it first"
+            )));
+        }
+        if is_local_uid(&uid) {
+            self.discard_local_node(&uid, &path)?;
+        } else {
+            self.discard_remote_change(&uid, &path)?;
+        }
+        info!(id, %uid, path, "discarded a queued change");
+        Ok(path)
+    }
+
+    /// Forget a node made here, and the ops that would have sent it.
+    fn discard_local_node(&self, uid: &NodeUid, path: &str) -> CoreResult<()> {
+        // Its children's ops go with its own, and their content with them.
+        if self
+            .db
+            .has_children(uid)
+            .map_err(|e| CoreError::internal(format!("listing {path}: {e}")))?
+        {
+            return Err(CoreError::conflict(format!(
+                "{path} is not empty; discard what is in it first"
+            )));
+        }
+        self.discard_queued_ops(uid)
+            .map_err(|_| CoreError::internal(format!("dropping the changes to {path}")))?;
+        self.for_each_mount(|st, notify| {
+            background::forget_and_notify(st, notify, uid);
+        });
+        self.cache.evict(uid);
+        self.evict_reader(uid);
+        Ok(())
+    }
+
+    /// Put a node Drive has back as Drive has it.
+    fn discard_remote_change(&self, uid: &NodeUid, path: &str) -> CoreResult<()> {
+        // Asked first: the change is only dropped once what replaces it is known.
+        let node = self
+            .fetch_node_remote(uid)
+            .map_err(|e| CoreError::from_api(&e, "reading the node from Drive"))?
+            .filter(|node| !node.trashed);
+        self.cancel_upload(uid);
+        let blobs = self
+            .db
+            .discard_ops_on_node(&uid.to_string())
+            .map_err(|e| CoreError::internal(format!("dropping the changes to {path}: {e}")))?
+            .ok_or_else(|| {
+                CoreError::conflict(format!("{path} is being sent right now; try again"))
+            })?;
+        self.release_dropped_ops(uid, blobs);
+        self.hidden.lock().remove(uid);
+        match node {
+            Some(node) => self.for_each_mount(|st, notify| {
+                put_back(st, notify, node);
+            }),
+            None => self.for_each_mount(|st, notify| {
+                background::forget_and_notify(st, notify, uid);
+            }),
+        }
+        self.cache.evict(uid);
+        self.evict_reader(uid);
+        Ok(())
+    }
+}
+
+/// Show `node` as Drive has it, where Drive has it, under the inode it has.
+fn put_back(st: &mut State, notify: &mut NotifyBatch, node: Node) {
+    let parent = node.parent_uid.as_ref().and_then(|parent| {
+        st.by_uid
+            .get(parent)
+            .copied()
+            .map(|ino| (ino, parent.clone()))
+    });
+    let here = st.by_uid.get(&node.uid).and_then(|ino| {
+        st.entries
+            .get(ino)
+            .map(|entry| (*ino, entry.parent, entry.node.name.clone()))
+    });
+    match (here, parent) {
+        (Some((ino, from, name)), Some((to, to_uid))) => {
+            st.relocate(ino, from, to, &to_uid, &node.name);
+            st.write_through(node.clone());
+            st.intern_mem(to, node);
+            notify.inval_entry(from, name);
+            notify.inval_inode(ino);
+        }
+        (here, parent) => {
+            if let Some((_, from, name)) = here {
+                st.forget_mem(&node.uid);
+                st.invalidate_listing(from);
+                notify.inval_entry(from, name);
+            }
+            if let Some((to, _)) = parent {
+                st.invalidate_listing(to);
+                notify.inval_entry(to, node.name.clone());
+            }
+            st.write_through(node);
+        }
+    }
+}
+
+/// Copy `blob` to `dest`, which must not exist: never replace something the
+/// user already has.
+fn copy_to_new_file(blob: &Path, dest: &Path) -> CoreResult<u64> {
+    let mut source = File::open(blob)
+        .map_err(|e| CoreError::internal(format!("open {}: {e}", blob.display())))?;
+    let mut out = std::fs::OpenOptions::new()
+        .write(true)
+        .create_new(true)
+        .open(dest)
+        .map_err(|e| match e.kind() {
+            std::io::ErrorKind::AlreadyExists => {
+                CoreError::invalid(format!("{} already exists", dest.display()))
+            }
+            _ => CoreError::internal(format!("create {}: {e}", dest.display())),
+        })?;
+    std::io::copy(&mut source, &mut out)
+        .and_then(|written| out.flush().and(out.sync_all()).map(|()| written))
+        .map_err(|e| CoreError::internal(format!("write {}: {e}", dest.display())))
+}
+
+/// The staged blob of an op that carries file content.
+fn exportable(op: &PendingOp) -> Option<&Path> {
+    matches!(op.kind.as_str(), OP_CREATE | OP_REVISION)
+        .then_some(op.blob_path.as_deref())
+        .flatten()
+        .map(Path::new)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn op(kind: &str, blob: Option<&str>) -> PendingOp {
+        PendingOp {
+            id: 1,
+            kind: kind.to_string(),
+            uid: "vol~a".to_string(),
+            parent_uid: None,
+            name: None,
+            blob_path: blob.map(str::to_string),
+            meta_json: None,
+            created_at: 0,
+            attempts: 0,
+            last_error: None,
+            next_attempt_at: 0,
+        }
+    }
+
+    #[test]
+    fn only_a_change_that_carries_file_content_can_be_exported() {
+        assert!(exportable(&op(OP_CREATE, Some("/staging/a"))).is_some());
+        assert!(exportable(&op(OP_REVISION, Some("/staging/a"))).is_some());
+        assert!(exportable(&op(OP_CREATE, None)).is_none());
+        assert!(exportable(&op(OP_RENAME, None)).is_none());
+        assert!(exportable(&op(OP_TRASH, None)).is_none());
+    }
+
+    #[test]
+    fn an_export_copies_the_bytes_and_never_replaces_a_file() {
+        let dir = std::env::temp_dir().join(format!("pdfs-export-{}", std::process::id()));
+        std::fs::create_dir_all(&dir).unwrap();
+        let blob = dir.join("blob");
+        std::fs::write(&blob, b"queued bytes").unwrap();
+
+        let dest = dir.join("copy.txt");
+        assert_eq!(copy_to_new_file(&blob, &dest).unwrap(), 12);
+        assert_eq!(std::fs::read(&dest).unwrap(), b"queued bytes");
+
+        std::fs::write(&dest, b"the user's own").unwrap();
+        assert!(copy_to_new_file(&blob, &dest).is_err());
+        assert_eq!(std::fs::read(&dest).unwrap(), b"the user's own");
+        // The staged blob is the only copy of the change: an export leaves it.
+        assert_eq!(std::fs::read(&blob).unwrap(), b"queued bytes");
+
+        let _ = std::fs::remove_dir_all(&dir);
+    }
 }
@@ -36,6 +36,21 @@ pub(super) const REPAIR_MAX: u64 = 512 * 1024 * 1024;
 /// demand read in the SDK's flat block semaphore.
 pub(super) const PREFETCH_BUDGET: usize = 8;

+/// How long one read may wait on the network before it fails with `EIO`.
+///
+/// The SDK bounds each request, not a read: a block that times out is retried,
+/// and a read can need several blocks, a block table and a repair. On a link
+/// that stalled without dropping, one `read` held a FUSE worker for 34 minutes
+/// and the application behind it with it (`docs/BUGS.md` B107). An error the
+/// caller can retry beats a process stuck in `D` state.
+pub(super) const READ_FETCH_TIMEOUT: Duration = Duration::from_secs(120);
+
+/// How long a read of blocks nothing has cached waits for a lost link to come
+/// back before failing. Long enough to ride out a Wi-Fi blip, short enough
+/// that a program reading while the laptop is really offline gets its `EIO`
+/// before the user gives up on it.
+const READ_OFFLINE_WAIT: Duration = Duration::from_secs(30);
+
 /// Cap on tracked sequential streams. Only reads in progress matter, so the map
 /// is cleared wholesale rather than aged — losing the ramp costs one read.
 const MAX_PREFETCH_STREAMS: usize = 256;
@@ -55,7 +70,7 @@ const MAX_OPEN_READERS: usize = 64;
 /// `(mtime, size)` — the same validity pair the content cache uses (a new
 /// revision bumps mtime). On a mismatch the reader is dropped and reopened.
 pub(super) struct CachedReader {
-    reader: Arc<RevisionReader>,
+    reader: Arc<dyn RevisionRead>,
    mtime: i64,
    size: u64,
    /// For LRU eviction.
@@ -86,7 +101,7 @@ pub(super) struct PendingOpen {
    /// must not join this open — it would get a reader for the wrong bytes.
    mtime: i64,
    size: u64,
-    rx: tokio::sync::watch::Receiver<Option<Result<Arc<RevisionReader>, Errno>>>,
+    rx: tokio::sync::watch::Receiver<Option<Result<Arc<dyn RevisionRead>, Errno>>>,
 }

 /// Distinguishes `PendingOpen`s. Only uniqueness matters, so a plain counter
@@ -298,16 +313,16 @@ impl Core {
        uid: &NodeUid,
        mtime: i64,
        fsize: u64,
-    ) -> Result<Arc<RevisionReader>, Errno> {
+    ) -> Result<Arc<dyn RevisionRead>, Errno> {
        loop {
            // Decide under the lock, act outside it — network I/O must never run
            // under a std `Mutex`, and an await must never hold one.
            enum Act {
-                Hit(Arc<RevisionReader>),
-                Join(tokio::sync::watch::Receiver<Option<Result<Arc<RevisionReader>, Errno>>>),
+                Hit(Arc<dyn RevisionRead>),
+                Join(tokio::sync::watch::Receiver<Option<Result<Arc<dyn RevisionRead>, Errno>>>),
                Lead(
                    u64,
-                    tokio::sync::watch::Sender<Option<Result<Arc<RevisionReader>, Errno>>>,
+                    tokio::sync::watch::Sender<Option<Result<Arc<dyn RevisionRead>, Errno>>>,
                ),
            }
            let act = {
@@ -361,9 +376,10 @@ impl Core {
                }
                Act::Lead(id, tx) => {
                    debug!(%uid, mtime, fsize, "opening revision");
-                    let result = match self.client.open_revision(uid).await {
-                        Ok(reader) => Ok(Arc::new(reader)),
+                    let result = match self.drive.open_revision(uid).await {
+                        Ok(reader) => Ok(reader),
                        Err(e) => {
+                            self.lost_link(&e, "open a revision");
                            warn!(%uid, error = %e, "open_revision failed");
                            Err(Errno::EIO)
                        }
@@ -448,7 +464,7 @@ impl Core {
    /// it, and the [`BLOCK_SIZE`] assumption when it has not — which is every
    /// first read, because learning it means opening a `RevisionReader`, and
    /// opening one per read is precisely the per-file key derivation the block
-    /// cache exists to avoid (bugs.md B12, B85).
+    /// cache exists to avoid (`docs/BUGS.md` B12, B85).
    ///
    /// Being wrong here is not a correctness problem: `read_at` plans over the
    /// real sizes and clamps to what was asked for either way. It costs a
@@ -477,15 +493,20 @@ impl Core {
    ) -> Result<Vec<u8>, Errno> {
        // A queued write has not reached the remote yet, so the remote's current
        // revision is stale and the staged blob is the truth. Serve from it until
-        // the drain worker lands the upload (offline.md Phase 3).
+        // the drain worker lands the upload.
        if let Some(pending) = self.pending.lock().get(uid).cloned() {
            return self.read_pending(&pending, offset, len);
        }
        // A node created offline and never written has no blob and no remote: it
        // is an empty file, and asking the API about a `local~` uid would only
-        // earn a 404 (offline.md Phase 3b).
+        // earn a 404. Unless its create landed since the
+        // read looked: the landing moved the queued write to the uid Drive
+        // gave it, and the row says which (`docs/BUGS.md` B179).
        if is_local_uid(uid) {
-            return Ok(Vec::new());
+            return match self.landed_stand_in_uid(uid) {
+                Some(real) => self.read_range(&real, mtime, fsize, offset, len, cache_blocks),
+                None => Ok(Vec::new()),
+            };
        }
        self.read_range_remote(uid, mtime, fsize, offset, len, cache_blocks)
    }
@@ -552,7 +573,7 @@ impl Core {
    /// leader's claim is gone by then, so this cannot recurse.
    async fn fetch_block(
        &self,
-        reader: &Arc<RevisionReader>,
+        reader: &Arc<dyn RevisionRead>,
        uid: &NodeUid,
        mtime: i64,
        fsize: u64,
@@ -615,10 +636,10 @@ impl Core {
    ///
    /// A block that comes back shorter than the file's size says it must be is
    /// never served, cached or promoted: it is repaired from the whole-file
-    /// download, or the read fails. See [`Core::repair_block`] (bugs.md B84).
+    /// download, or the read fails. See [`Core::repair_block`] (`docs/BUGS.md` B84).
    async fn read_block(
        &self,
-        reader: &Arc<RevisionReader>,
+        reader: &Arc<dyn RevisionRead>,
        uid: &NodeUid,
        mtime: i64,
        fsize: u64,
@@ -630,7 +651,7 @@ impl Core {
        // file's boundaries are wrong, and the failure is not confined to short
        // reads: sizes that *overstate* a block shift every block after it and
        // return full-length reads of the wrong bytes. So a disagreement of any
-        // kind takes the file off the range path entirely (bugs.md B84).
+        // kind takes the file off the range path entirely (`docs/BUGS.md` B84).
        let bytes = if reader.size() != fsize {
            warn!(
                %uid, bidx = span.idx, fsize,
@@ -643,12 +664,13 @@ impl Core {
            // Learned here rather than on a path of its own: this is where a
            // reader is open anyway, and recording the real geometry is what
            // lets the *next* read plan its blocks on the revision's own
-            // boundaries instead of the 4 MiB fallback (bugs.md B85).
+            // boundaries instead of the 4 MiB fallback (`docs/BUGS.md` B85).
            if cache_blocks {
                self.cache
                    .store_block_geometry(uid, mtime, fsize, reader.block_sizes());
            }
            let bytes = reader.read_at(span.start, span.len).await.map_err(|e| {
+                self.lost_link(&e, "read a block");
                warn!(%uid, start = span.start, len = span.len, error = %e, "block read failed");
                Errno::EIO
            })?;
@@ -684,7 +706,7 @@ impl Core {
    /// The range path derives every block boundary from the revision's recorded
    /// block sizes. When those understate the file, reads come back short with
    /// no error anywhere, and the caller hands userspace a truncated file that
-    /// looks like a clean EOF (bugs.md B84). `download_file_to` does not do that
+    /// looks like a clean EOF (`docs/BUGS.md` B84). `download_file_to` does not do that
    /// arithmetic — it streams the block list — so it returns the whole file
    /// where the range path cannot, which is why pinning was the workaround.
    /// This does the same thing on the user's behalf, once, and the resulting
@@ -761,7 +783,7 @@ impl Core {
            error!(%uid, %error, "creating a scratch file for a repair download failed");
            Errno::EIO
        })?;
-        let outcome = self.client.download_file_to(uid, &mut file).await;
+        let outcome = self.drive.download_file_to(uid, &mut file).await;
        let stored = (|| {
            outcome.map_err(|error| {
                warn!(%uid, %error, "repair download failed");
@@ -896,7 +918,7 @@ impl Core {
        let end = offset.saturating_add(len).min(fsize);
        let mut out = Vec::with_capacity((end - offset) as usize);
        // On the revision's own boundaries where they are known, and on the
-        // 4 MiB fallback where they are not (bugs.md B85).
+        // 4 MiB fallback where they are not (`docs/BUGS.md` B85).
        let wanted = self.block_geometry(uid, mtime, fsize).spans(offset, end);
        let (Some(&head), Some(&tail)) = (wanted.first(), wanted.last()) else {
            return Ok(out);
@@ -939,28 +961,67 @@ impl Core {
        }

        if !misses.is_empty() {
-            let fetched = self.rt.block_on(async {
-                // Resolve the file's keys and block table once, then read every
-                // missing block through the shared reader. Previously each block
-                // called `download_range`, which redid that resolution per block.
-                let reader = self.revision_reader(uid, mtime, fsize).await?;
+            // One deadline for the whole read, including any wait for a lost
+            // link. A fetch that failed because the link went down is tried
+            // once more when it is back, so a blip is a slow read, not an `EIO`.
+            let deadline = Instant::now() + READ_FETCH_TIMEOUT;
+            let mut retried = false;
+            let fetched = loop {
+                if !self.is_online() {
+                    let wait =
+                        READ_OFFLINE_WAIT.min(deadline.saturating_duration_since(Instant::now()));
+                    if !self.wait_online(wait) {
+                        debug!(%uid, offset, len, "read of uncached blocks while offline; failing it");
+                        return Err(Errno::EIO);
+                    }
+                }
+                let fetch = async {
+                    // Resolve the file's keys and block table once, then read every
+                    // missing block through the shared reader. Previously each block
+                    // called `download_range`, which redid that resolution per block.
+                    let reader = self.revision_reader(uid, mtime, fsize).await?;

-                let mut set = tokio::task::JoinSet::new();
-                for &span in &misses {
-                    let (core, reader, uid) = (self.clone(), reader.clone(), uid.clone());
-                    set.spawn(async move {
-                        core.fetch_block(&reader, &uid, mtime, fsize, span, cache_blocks)
-                            .await
-                            .map(|bytes| (span.idx, bytes))
-                    });
+                    let mut set = tokio::task::JoinSet::new();
+                    for &span in &misses {
+                        let (core, reader, uid) = (self.clone(), reader.clone(), uid.clone());
+                        set.spawn(async move {
+                            core.fetch_block(&reader, &uid, mtime, fsize, span, cache_blocks)
+                                .await
+                                .map(|bytes| (span.idx, bytes))
+                        });
+                    }
+                    let mut out = Vec::with_capacity(misses.len());
+                    while let Some(joined) = set.join_next().await {
+                        // A join error means the task panicked; surface it as EIO.
+                        out.push(joined.map_err(|_| Errno::EIO)??);
+                    }
+                    Ok::<_, Errno>(out)
+                };
+                // Dropping the fetch on the deadline aborts the block tasks with
+                // it; blocks that already landed stay cached for the retry. The
+                // timer is built inside the runtime: a FUSE worker has no reactor
+                // of its own, and building it out here panicked every remote read.
+                let budget = deadline.saturating_duration_since(Instant::now());
+                match self
+                    .rt
+                    .block_on(async { tokio::time::timeout(budget, fetch).await })
+                {
+                    Ok(Ok(fetched)) => break fetched,
+                    // The fetch saw the link go down; the top of the loop waits
+                    // for it within what is left of the deadline.
+                    Ok(Err(_)) if !retried && !self.is_online() => retried = true,
+                    Ok(Err(e)) => return Err(e),
+                    Err(_) => {
+                        warn!(
+                            %uid, offset, len, secs = READ_FETCH_TIMEOUT.as_secs(),
+                            "read got no answer from the network in time; failing it"
+                        );
+                        self.evict_reader(uid);
+                        self.mark_offline("read", &crate::link::no_answer(READ_FETCH_TIMEOUT));
+                        return Err(Errno::EIO);
+                    }
                }
-                let mut out = Vec::with_capacity(misses.len());
-                while let Some(joined) = set.join_next().await {
-                    // A join error means the task panicked; surface it as EIO.
-                    out.push(joined.map_err(|_| Errno::EIO)??);
-                }
-                Ok::<_, Errno>(out)
-            })?;
+            };
            for (bidx, bytes) in fetched {
                blocks[(bidx - first) as usize] = Some(bytes);
            }
@@ -977,7 +1038,7 @@ impl Core {
            // — the cache validates it on read, the network path in `read_block`
            // — so this refuses rather than quietly contributing fewer bytes
            // than the range covers, which is what turned a bad block into a
-            // truncated file (bugs.md B84).
+            // truncated file (`docs/BUGS.md` B84).
            if block.len() as u64 != span.len {
                error!(
                    %uid, bidx = span.idx, len = block.len(), expected = span.len, fsize,
@@ -248,10 +248,7 @@ impl Core {

        let outcomes = self
            .rt
-            .block_on(
-                self.client
-                    .trash_nodes(std::slice::from_ref(&candidate.uid)),
-            )
+            .block_on(self.drive.trash_nodes(std::slice::from_ref(&candidate.uid)))
            .map_err(|e| CoreError::from_api(&e, "trash the mis-dated original"))?;
        if let Some((_, Err(e))) = outcomes.into_iter().next() {
            return Err(CoreError::from_api(&e, "trash the mis-dated original"));
@@ -0,0 +1,611 @@
+//! Moving a file or folder between two locations without moving its content.
+//!
+//! `~/ProtonDrive` and every on-demand synced folder are separate FUSE
+//! sessions, and a mirror folder is a plain local directory. The kernel refuses
+//! `rename(2)` between two mounts with `EXDEV` before the daemon hears of it, so
+//! `mv` falls back to copy and delete: every file is downloaded, uploaded again,
+//! and the original is trashed.
+//!
+//! On Proton Drive the same move is one metadata change, because My files and
+//! this computer's device folders all live on the main volume. So a move
+//! request that names two absolute paths is resolved here, against every
+//! location this daemon knows, and done as a server-side move. The local side
+//! is then brought level: a mount forgets the node and re-lists, and a mirror
+//! folder either renames its copy along or drops it once Drive has it.
+
+use std::collections::HashMap;
+use std::path::{Component, Path, PathBuf};
+use std::sync::Arc;
+use std::time::Duration;
+
+use parking_lot::Mutex;
+use pdfs_core::db::{StoredSyncEntry, StoredSyncFolder};
+use pdfs_core::{CoreError, CoreResult};
+use proton_drive_rs::NodeKind;
+use proton_drive_rs::proton_sdk::ids::NodeUid;
+use tracing::{info, warn};
+
+use super::sync::mirror_subtree_unsynced;
+use super::{Core, is_local_uid, parse_uid};
+
+/// How long a move waits for a mirror folder's sync pass to finish before it
+/// reports the folder busy. A pass can run for hours on a first sync, so the
+/// move does not wait it out.
+const MIRROR_LOCK_WAIT: Duration = Duration::from_secs(5);
+
+/// Where one side of a move lives.
+enum Place {
+    /// My files or an on-demand folder: a live FUSE mount. `core` is rooted at
+    /// that mount and `rel` is relative to its mountpoint.
+    Mounted { core: Box<Core>, rel: PathBuf },
+    /// A mirror folder: a local directory kept in step by the sync engine.
+    /// `rel` is `/`-separated, relative to the folder, as the baseline keys it.
+    Mirror {
+        folder: StoredSyncFolder,
+        rel: String,
+    },
+}
+
+impl Place {
+    fn mirror_id(&self) -> Option<i64> {
+        match self {
+            Place::Mirror { folder, .. } => Some(folder.id),
+            Place::Mounted { .. } => None,
+        }
+    }
+
+    fn is_root(&self) -> bool {
+        match self {
+            Place::Mounted { rel, .. } => rel.as_os_str().is_empty(),
+            Place::Mirror { rel, .. } => rel.is_empty(),
+        }
+    }
+}
+
+/// The mirror folder that holds `abs`, and `abs` relative to it. The deepest
+/// folder wins, although folders are not expected to nest.
+fn mirror_covering(
+    folders: Vec<StoredSyncFolder>,
+    abs: &Path,
+) -> Option<(StoredSyncFolder, String)> {
+    let folder = folders
+        .into_iter()
+        .filter(|f| f.mode == "mirror" && abs.starts_with(&f.local_path))
+        .max_by_key(|f| Path::new(&f.local_path).components().count())?;
+    let rel = abs.strip_prefix(&folder.local_path).ok()?;
+    let parts = rel
+        .components()
+        .map(|c| match c {
+            Component::Normal(part) => part.to_str(),
+            _ => None,
+        })
+        .collect::<Option<Vec<_>>>()?;
+    Some((folder, parts.join("/")))
+}
+
+/// `name` inside the folder at `parent`, in baseline form.
+fn join_rel(parent: &str, name: &str) -> String {
+    if parent.is_empty() {
+        name.to_string()
+    } else {
+        format!("{parent}/{name}")
+    }
+}
+
+/// Rename `from` to `to`, failing with `EEXIST` rather than replacing
+/// whatever appeared at `to` since it was checked. A filesystem that cannot
+/// promise that gets a plain rename after one more look.
+fn rename_noreplace(from: &Path, to: &Path) -> std::io::Result<()> {
+    use std::ffi::CString;
+    use std::os::unix::ffi::OsStrExt;
+
+    let cstr = |p: &Path| {
+        CString::new(p.as_os_str().as_bytes())
+            .map_err(|_| std::io::Error::from_raw_os_error(libc::EINVAL))
+    };
+    let (c_from, c_to) = (cstr(from)?, cstr(to)?);
+    // SAFETY: both are valid NUL-terminated paths that outlive the call.
+    let rc = unsafe {
+        libc::syscall(
+            libc::SYS_renameat2,
+            libc::AT_FDCWD,
+            c_from.as_ptr(),
+            libc::AT_FDCWD,
+            c_to.as_ptr(),
+            libc::RENAME_NOREPLACE,
+        )
+    };
+    if rc == 0 {
+        return Ok(());
+    }
+    let err = std::io::Error::last_os_error();
+    match err.raw_os_error() {
+        Some(libc::EINVAL | libc::ENOSYS) => {
+            if std::fs::symlink_metadata(to).is_ok() {
+                return Err(std::io::Error::from_raw_os_error(libc::EEXIST));
+            }
+            std::fs::rename(from, to)
+        }
+        _ => Err(err),
+    }
+}
+
+/// Whether `uid` is `root` or lies under it, as far as the nodes table knows.
+fn under(core: &Core, root: &NodeUid, uid: &str) -> bool {
+    let root = root.to_string();
+    uid == root || matches!(core.db.path_relative_to(&root, uid), Ok(Some(_)))
+}
+
+impl Core {
+    /// Move the file or folder at `src` into the folder at `dest_parent`. Both
+    /// are absolute local paths and may be in different locations: My files,
+    /// an on-demand folder, or a mirror folder. Returns the moved name.
+    ///
+    /// Within one mount this is [`Core::move_to`]. Across locations it
+    /// is a server-side move followed by local bookkeeping; see the module
+    /// documentation. Anything the move could lose is refused up front.
+    pub(crate) fn move_between(&self, src: &Path, dest_parent: &Path) -> CoreResult<String> {
+        let source = self.locate(src)?;
+        let dest = self.locate(dest_parent)?;
+        if let (
+            Place::Mounted { core, rel },
+            Place::Mounted {
+                core: dest_core,
+                rel: dest_rel,
+            },
+        ) = (&source, &dest)
+            && Arc::ptr_eq(&core.root, &dest_core.root)
+        {
+            return core.move_to(rel, dest_rel);
+        }
+        if source.is_root() {
+            return Err(CoreError::invalid(format!(
+                "{} is the root of a synced location and cannot be moved",
+                src.display()
+            )));
+        }
+        if dest_parent.starts_with(src) {
+            return Err(CoreError::invalid("cannot move a folder into itself"));
+        }
+        let name = src
+            .file_name()
+            .and_then(|n| n.to_str())
+            .ok_or_else(|| CoreError::invalid(format!("{} has no usable name", src.display())))?
+            .to_string();
+
+        // Hold every mirror folder involved, lowest id first, so no sync pass
+        // sees the move half done and two moves cannot deadlock.
+        let mut ids: Vec<i64> = [source.mirror_id(), dest.mirror_id()]
+            .into_iter()
+            .flatten()
+            .collect();
+        ids.sort_unstable();
+        ids.dedup();
+        let locks: Vec<Arc<Mutex<()>>> = ids.iter().map(|&id| self.sync_lock(id)).collect();
+        let mut guards = Vec::with_capacity(locks.len());
+        for lock in &locks {
+            guards.push(lock.try_lock_for(MIRROR_LOCK_WAIT).ok_or_else(|| {
+                CoreError::conflict("a synced folder is busy syncing; try again when it is done")
+            })?);
+        }
+
+        let mut baselines: HashMap<i64, HashMap<String, StoredSyncEntry>> = HashMap::new();
+        for &id in &ids {
+            let baseline = self
+                .db
+                .sync_entries(id)
+                .map_err(|e| CoreError::internal(format!("db: {e}")))?;
+            baselines.insert(id, baseline);
+        }
+
+        let src_uid = self.source_uid(&source, &baselines)?;
+        let dest_uid = self.dest_uid(&dest, &baselines, &name)?;
+        if src_uid.volume_id != dest_uid.volume_id {
+            return Err(CoreError::invalid(
+                "the two locations are on different Proton Drive volumes; copy it instead",
+            ));
+        }
+        if under(self, &src_uid, &dest_uid.to_string()) {
+            return Err(CoreError::invalid("cannot move a folder into itself"));
+        }
+
+        // Mirror to mirror renames the local copy along, so it needs nothing
+        // proven about it. Another filesystem makes that impossible, and the
+        // pair then drops the source copy like any other move out of a mirror.
+        let mut renamed = None;
+        if let (
+            Place::Mirror { folder, rel },
+            Place::Mirror {
+                folder: dest_folder,
+                rel: dest_rel,
+            },
+        ) = (&source, &dest)
+        {
+            let from = src.to_path_buf();
+            let to = dest_parent.join(&name);
+            match rename_noreplace(&from, &to) {
+                Ok(()) => renamed = Some((from, to)),
+                Err(e) if e.raw_os_error() == Some(libc::EXDEV) => {
+                    info!(from = %folder.local_path, to = %dest_folder.local_path,
+                        "move: mirror folders are on different filesystems");
+                }
+                Err(e) if e.raw_os_error() == Some(libc::EEXIST) => {
+                    return Err(CoreError::conflict(format!(
+                        "{name} already exists in {}",
+                        dest_parent.display()
+                    )));
+                }
+                Err(e) => {
+                    return Err(CoreError::internal(format!(
+                        "could not move {} to {}: {e}",
+                        rel,
+                        join_rel(dest_rel, &name)
+                    )));
+                }
+            }
+        }
+        if renamed.is_none()
+            && let Place::Mirror { folder, rel } = &source
+            && let Some(reason) =
+                mirror_subtree_unsynced(Path::new(&folder.local_path), rel, &baselines[&folder.id])
+        {
+            return Err(CoreError::conflict(format!(
+                "{name} is not fully synced yet ({reason}); wait for the sync to finish"
+            )));
+        }
+
+        if let Err(e) = self.move_remote(&src_uid, &dest_uid) {
+            if let Some((from, to)) = &renamed
+                && let Err(back) = std::fs::rename(to, from)
+            {
+                warn!(from = %to.display(), to = %from.display(), error = %back,
+                    "move: could not put the local copy back after the move failed");
+            }
+            return Err(CoreError::from_api(&e, "move"));
+        }
+
+        self.settle_source(
+            &source,
+            &src_uid,
+            renamed.is_some(),
+            &dest,
+            &dest_uid,
+            &name,
+            src,
+        );
+        self.settle_dest(&dest, &dest_uid, &name);
+        drop(guards);
+        if renamed.is_none()
+            && let Place::Mirror { folder, .. } = &dest
+        {
+            // Nothing local exists yet; the folder's next pass downloads it.
+            self.sync_now(Some(folder.id));
+        }
+        Ok(name)
+    }
+
+    /// Which location `abs` is in. A mount is looked for first: a mirror folder
+    /// cannot live inside a FUSE mount, and a mount is what the kernel sees.
+    fn locate(&self, abs: &Path) -> CoreResult<Place> {
+        if let Some((core, rel)) = self.rooted_at(abs) {
+            if !rel
+                .components()
+                .all(|c| matches!(c, Component::Normal(_) | Component::CurDir))
+            {
+                return Err(CoreError::invalid(format!(
+                    "{} escapes its location",
+                    abs.display()
+                )));
+            }
+            return Ok(Place::Mounted {
+                core: Box::new(core),
+                rel,
+            });
+        }
+        let folders = self
+            .db
+            .sync_folder_list()
+            .map_err(|e| CoreError::internal(format!("db: {e}")))?;
+        mirror_covering(folders, abs)
+            .map(|(folder, rel)| Place::Mirror { folder, rel })
+            .ok_or_else(|| {
+                CoreError::invalid(format!(
+                    "{} is not in a Proton Drive location",
+                    abs.display()
+                ))
+            })
+    }
+
+    /// The node being moved, once everything that must hold before it leaves
+    /// its location has been checked.
+    fn source_uid(
+        &self,
+        source: &Place,
+        baselines: &HashMap<i64, HashMap<String, StoredSyncEntry>>,
+    ) -> CoreResult<NodeUid> {
+        match source {
+            Place::Mounted { core, rel } => {
+                let (ino, uid) = core.resolve(rel)?;
+                if is_local_uid(&uid) {
+                    return Err(CoreError::conflict(
+                        "it is not uploaded yet; wait for the upload to finish",
+                    ));
+                }
+                let old_parent = core.source_parent_uid(ino, rel)?;
+                for authority in [&uid, &old_parent] {
+                    core.require_uid_writable(authority)
+                        .map_err(|e| core.errno_error(e, "move access"))?;
+                }
+                if self.has_pending_work_under(&uid)? {
+                    return Err(CoreError::conflict(
+                        "it has changes that are not uploaded yet; wait for the upload to finish",
+                    ));
+                }
+                Ok(uid)
+            }
+            Place::Mirror { folder, rel } => baselines[&folder.id]
+                .get(rel)
+                .and_then(|entry| entry.remote_uid.as_deref())
+                .and_then(parse_uid)
+                .ok_or_else(|| {
+                    CoreError::conflict(
+                        "it is not on Proton Drive yet; wait for the sync to finish",
+                    )
+                }),
+        }
+    }
+
+    /// The folder the node moves into. Refuses one that already holds `name`
+    /// on this disk; Drive refuses a clash on its side by itself.
+    fn dest_uid(
+        &self,
+        dest: &Place,
+        baselines: &HashMap<i64, HashMap<String, StoredSyncEntry>>,
+        name: &str,
+    ) -> CoreResult<NodeUid> {
+        let uid = match dest {
+            Place::Mounted { core, rel } => {
+                let (ino, uid) = core.resolve(rel)?;
+                let is_folder = core
+                    .state()
+                    .entries
+                    .get(&ino)
+                    .is_some_and(|entry| matches!(entry.node.kind, NodeKind::Folder));
+                if !is_folder {
+                    return Err(CoreError::invalid("the destination is not a folder"));
+                }
+                core.require_uid_writable(&uid)
+                    .map_err(|e| core.errno_error(e, "move access"))?;
+                uid
+            }
+            Place::Mirror { folder, rel } => {
+                let local = Path::new(&folder.local_path).join(rel);
+                if !local.is_dir() {
+                    return Err(CoreError::invalid("the destination is not a folder"));
+                }
+                if std::fs::symlink_metadata(local.join(name)).is_ok() {
+                    return Err(CoreError::conflict(format!(
+                        "{name} already exists in the destination"
+                    )));
+                }
+                let uid = if rel.is_empty() {
+                    Some(folder.remote_uid.as_str())
+                } else {
+                    baselines[&folder.id]
+                        .get(rel)
+                        .and_then(|entry| entry.remote_uid.as_deref())
+                };
+                uid.and_then(parse_uid).ok_or_else(|| {
+                    CoreError::conflict(
+                        "the destination is not on Proton Drive yet; wait for the sync to finish",
+                    )
+                })?
+            }
+        };
+        if is_local_uid(&uid) {
+            return Err(CoreError::conflict(
+                "the destination is not uploaded yet; wait for the upload to finish",
+            ));
+        }
+        Ok(uid)
+    }
+
+    /// Whether the queue owes Drive anything for `uid` or a node under it, or a
+    /// file under it is open for writing. Moving such a node away would strand
+    /// the pending change against a path that no longer leads to it.
+    fn has_pending_work_under(&self, uid: &NodeUid) -> CoreResult<bool> {
+        let ops = self
+            .db
+            .pending_ops()
+            .map_err(|e| CoreError::internal(format!("db: {e}")))?;
+        if ops.iter().any(|op| {
+            under(self, uid, &op.uid)
+                || op
+                    .parent_uid
+                    .as_deref()
+                    .is_some_and(|p| under(self, uid, p))
+        }) {
+            return Ok(true);
+        }
+        // Collected first so no State lock is held across the nodes-table reads.
+        let mut writing = Vec::new();
+        self.for_each_state(|st| {
+            writing.extend(st.active_writes.values().map(|w| w.uid.to_string()));
+        });
+        Ok(writing.iter().any(|w| under(self, uid, w)))
+    }
+
+    /// Bring the source location level with a move Drive has made.
+    #[allow(clippy::too_many_arguments)]
+    fn settle_source(
+        &self,
+        source: &Place,
+        uid: &NodeUid,
+        renamed: bool,
+        dest: &Place,
+        dest_uid: &NodeUid,
+        name: &str,
+        src: &Path,
+    ) {
+        match source {
+            Place::Mounted { core, rel } => {
+                // Moved everywhere, so no mount keeps serving it under the old
+                // path and its row stays (`docs/BUGS.md` B117). The content
+                // cache is keyed by uid and stays valid.
+                self.relocate_everywhere(uid, dest_uid, name);
+                core.invalidate_parent_listing(rel);
+            }
+            Place::Mirror { folder, rel } if renamed => {
+                let Place::Mirror {
+                    folder: dest_folder,
+                    rel: dest_rel,
+                } = dest
+                else {
+                    unreachable!("a local rename needs a mirror destination");
+                };
+                if let Err(e) = self.db.sync_entries_move(
+                    folder.id,
+                    rel,
+                    dest_folder.id,
+                    &join_rel(dest_rel, name),
+                ) {
+                    // The next passes see a copy with no baseline on one side
+                    // and a baseline with no copy on the other. That uploads
+                    // the files again and trashes the moved node, but loses
+                    // nothing.
+                    warn!(error = ?e, "move: could not carry the sync baseline along");
+                }
+            }
+            Place::Mirror { folder, rel } => {
+                // Drive had all of it when the move was checked, so the local
+                // copy is only a stale duplicate now. Something written into it
+                // since would go with it, so look again first; if anything is
+                // new, the copy stays and the next pass uploads it as new.
+                let changed = match self.db.sync_entries(folder.id) {
+                    Ok(baseline) => {
+                        mirror_subtree_unsynced(Path::new(&folder.local_path), rel, &baseline)
+                    }
+                    Err(e) => Some(format!("db: {e}")),
+                };
+                if let Err(e) = self.db.sync_entries_remove_subtree(folder.id, rel) {
+                    warn!(error = ?e, "move: could not drop the sync baseline");
+                }
+                if let Some(reason) = changed {
+                    warn!(path = %src.display(), reason,
+                        "move: the local copy changed during the move; keeping it");
+                    return;
+                }
+                let removed = if src.is_dir() {
+                    std::fs::remove_dir_all(src)
+                } else {
+                    std::fs::remove_file(src)
+                };
+                if let Err(e) = removed {
+                    warn!(path = %src.display(), error = %e,
+                        "move: could not remove the local copy after the move");
+                }
+            }
+        }
+    }
+
+    /// Bring the destination location level with a move Drive has made.
+    fn settle_dest(&self, dest: &Place, uid: &NodeUid, name: &str) {
+        if let Place::Mounted { .. } = dest {
+            self.invalidate_children_of(uid);
+            // A lookup that missed before the move may be cached as absent.
+            self.for_each_mount(|st, notify| {
+                if let Some(&ino) = st.by_uid.get(uid) {
+                    notify.inval_entry(ino, name.to_string());
+                }
+            });
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn folder(id: i64, local_path: &str, mode: &str) -> StoredSyncFolder {
+        StoredSyncFolder {
+            id,
+            local_path: local_path.to_string(),
+            remote_uid: format!("vol~root{id}"),
+            remote_share_id: String::new(),
+            mode: mode.to_string(),
+            pending_mode: None,
+            state: "idle".to_string(),
+            last_sync: 0,
+        }
+    }
+
+    #[test]
+    fn mirror_covering_finds_the_mirror_folder_and_the_path_inside_it() {
+        let folders = vec![folder(1, "/home/u/Docs", "mirror")];
+        let (found, rel) = mirror_covering(folders, Path::new("/home/u/Docs/a/b.txt")).unwrap();
+        assert_eq!(found.id, 1);
+        assert_eq!(rel, "a/b.txt");
+    }
+
+    #[test]
+    fn mirror_covering_gives_an_empty_path_for_the_folder_itself() {
+        let folders = vec![folder(1, "/home/u/Docs", "mirror")];
+        let (_, rel) = mirror_covering(folders, Path::new("/home/u/Docs")).unwrap();
+        assert_eq!(rel, "");
+    }
+
+    #[test]
+    fn mirror_covering_prefers_the_deepest_folder() {
+        let folders = vec![
+            folder(1, "/home/u/Docs", "mirror"),
+            folder(2, "/home/u/Docs/Work", "mirror"),
+        ];
+        let (found, rel) = mirror_covering(folders, Path::new("/home/u/Docs/Work/x")).unwrap();
+        assert_eq!(found.id, 2);
+        assert_eq!(rel, "x");
+    }
+
+    #[test]
+    fn mirror_covering_skips_on_demand_folders_and_name_prefixed_siblings() {
+        let folders = || {
+            vec![
+                folder(1, "/home/u/Docs", "mirror"),
+                folder(2, "/home/u/Media", "ondemand"),
+            ]
+        };
+        assert!(mirror_covering(folders(), Path::new("/home/u/Media/x")).is_none());
+        assert!(mirror_covering(folders(), Path::new("/home/u/Docs2/x")).is_none());
+    }
+
+    #[test]
+    fn mirror_covering_refuses_a_path_that_climbs_out() {
+        let folders = vec![folder(1, "/home/u/Docs", "mirror")];
+        assert!(mirror_covering(folders, Path::new("/home/u/Docs/../etc")).is_none());
+    }
+
+    #[test]
+    fn join_rel_names_a_child_of_the_folder_root_without_a_slash() {
+        assert_eq!(join_rel("", "a"), "a");
+        assert_eq!(join_rel("x/y", "a"), "x/y/a");
+    }
+
+    #[test]
+    fn a_local_rename_never_replaces_what_is_already_there() {
+        let dir = std::env::temp_dir().join(format!("pdfs-relocate-{}", std::process::id()));
+        let _ = std::fs::remove_dir_all(&dir);
+        std::fs::create_dir_all(&dir).unwrap();
+        let (a, b, c) = (dir.join("a"), dir.join("b"), dir.join("c"));
+        std::fs::write(&a, b"moved").unwrap();
+        std::fs::write(&b, b"kept").unwrap();
+
+        let err = rename_noreplace(&a, &b).unwrap_err();
+        assert_eq!(err.raw_os_error(), Some(libc::EEXIST));
+        assert_eq!(std::fs::read(&b).unwrap(), b"kept");
+        assert!(a.exists());
+
+        rename_noreplace(&a, &c).unwrap();
+        assert!(!a.exists());
+        assert_eq!(std::fs::read(&c).unwrap(), b"moved");
+        std::fs::remove_dir_all(&dir).unwrap();
+    }
+}
@@ -232,7 +232,7 @@ impl Core {
        let mut out = std::io::BufWriter::new(file);
        let written = match self
            .rt
-            .block_on(self.client.download_revision_to(uid, revision_id, &mut out))
+            .block_on(self.drive.download_revision_to(uid, revision_id, &mut out))
            .map_err(|e| CoreError::from_api(&e, "download revision"))
            .and_then(|()| {
                use std::io::Write as _;
@@ -21,7 +21,7 @@ use proton_drive_rs::{MemberRole, NodeKind};

 use proton_drive_rs::Node;

-use super::{Core, ROOT_INO, node_size, parse_uid, public_link_info, role_from_str, role_to_str};
+use super::{Core, node_size, parse_uid, public_link_info, role_from_str, role_to_str};

 /// A node from a *shared* listing as a [`DirEntry`].
 ///
@@ -75,6 +75,7 @@ fn shared_entry_of(core: &Core, n: Node) -> DirEntry {
        shared_by_unverified,
        trashed_at: 0,
        trashed_from: None,
+        issue: None,
    }
 }

@@ -463,7 +464,7 @@ impl Core {
        }
        let nodes = self
            .rt
-            .block_on(self.client.enumerate_nodes(&uids))
+            .block_on(self.drive.enumerate_nodes(&uids))
            .map_err(|e| CoreError::from_api(&e, "enumerate nodes"))?;
        Ok(nodes
            .into_iter()
@@ -481,14 +482,14 @@ impl Core {
            parse_uid(uid).ok_or_else(|| CoreError::invalid(format!("invalid uid: {uid}")))?;
        let child_uids = self
            .rt
-            .block_on(self.client.enumerate_folder_children_node_uids(&uid))
+            .block_on(self.drive.enumerate_folder_children_node_uids(&uid))
            .map_err(|e| CoreError::from_api(&e, "enumerate shared children"))?;
        if child_uids.is_empty() {
            return Ok(Vec::new());
        }
        let nodes = self
            .rt
-            .block_on(self.client.enumerate_nodes(&child_uids))
+            .block_on(self.drive.enumerate_nodes(&child_uids))
            .map_err(|e| CoreError::from_api(&e, "enumerate nodes"))?;
        Ok(nodes
            .into_iter()
@@ -509,7 +510,7 @@ impl Core {
            parse_uid(uid).ok_or_else(|| CoreError::invalid(format!("invalid uid: {uid}")))?;
        let node = self
            .rt
-            .block_on(self.client.get_node(&uid))
+            .block_on(self.drive.get_node(&uid))
            .map_err(|e| CoreError::from_api(&e, "get shared node"))?
            .ok_or_else(|| CoreError::not_found("shared node not found"))?;
        if !node.is_file() {
@@ -610,10 +611,10 @@ impl Core {
    /// Proton products (not Drive-only). A remote round-trip; nothing here is
    /// cached.
    pub(crate) fn account_quota(&self) -> CoreResult<(i64, i64)> {
-        let q = self
-            .rt
-            .block_on(self.client.quota())
-            .map_err(|e| CoreError::from_api(&e, "account quota"))?;
+        let q = self.block_on_bounded(self.drive.quota()).map_err(|e| {
+            self.lost_link(&e, "account quota");
+            CoreError::from_api(&e, "account quota")
+        })?;
        *self.quota.lock() = Some((std::time::Instant::now(), q.max_space, q.used_space));
        Ok((q.max_space, q.used_space))
    }
@@ -632,11 +633,22 @@ impl Core {
        {
            return Some((max_space, used_space));
        }
-        match self.account_quota() {
+        let last = || self.quota.lock().map(|(_, max, used)| (max, used));
+        if !self.is_online()
+            || self
+                .quota_refreshing
+                .swap(true, std::sync::atomic::Ordering::AcqRel)
+        {
+            return last();
+        }
+        let refreshed = self.account_quota();
+        self.quota_refreshing
+            .store(false, std::sync::atomic::Ordering::Release);
+        match refreshed {
            Ok(q) => Some(q),
            Err(error) => {
                debug!(%error, "account quota refresh failed; serving the last known figures");
-                self.quota.lock().map(|(_, max, used)| (max, used))
+                last()
            }
        }
    }
@@ -658,7 +670,7 @@ impl Core {
        }
        let nodes = self
            .rt
-            .block_on(self.client.enumerate_nodes(&uids))
+            .block_on(self.drive.enumerate_nodes(&uids))
            .map_err(|e| CoreError::from_api(&e, "enumerate nodes"))?;
        let mut items = Vec::with_capacity(nodes.len());
        for n in nodes {
@@ -703,19 +715,10 @@ impl Core {
    /// been seen through the mount (e.g. shared but not browsed to this session) —
    /// the caller then leaves the path empty.
    pub(crate) fn rel_path_for_uid(&self, uid: &NodeUid) -> Option<String> {
-        // Searched across every mount: a node browsed through a sync folder is
-        // interned in that fork's inode space, so the primary state alone had no
-        // entry for it and the caller silently showed an empty path
-        // (`docs/BUGS.md` B74). The path is relative to whichever mount holds
-        // it, which is the one the user reached it through.
-        let mut path = None;
-        self.for_each_state(|st| {
-            if path.is_some() {
-                return;
-            }
-            path = walk_to_root(st, uid);
-        });
-        path
+        // Relative to whichever root the node sits under: a node browsed
+        // through a sync folder is under that fork's root, not My Files
+        // (`docs/BUGS.md` B74).
+        walk_to_root(&self.state(), uid)
    }
 }

@@ -760,14 +763,18 @@ impl StopSharingOutcome {
    }
 }

-/// Walk one inode space from `uid` up to its root, building the path. `None` if
-/// that mount has never interned the node, or if the chain breaks partway —
+/// Walk the tree from `uid` up to the root it sits under, building the path.
+/// `None` if the node has never been interned, or if the chain breaks partway —
 /// a broken chain is a missing path, never a partial one.
 fn walk_to_root(st: &super::State, uid: &NodeUid) -> Option<String> {
    let mut ino = *st.by_uid.get(uid)?;
    let mut parts = Vec::new();
-    while ino != ROOT_INO {
+    while !st.roots.contains(&ino) {
        let entry = st.entries.get(&ino)?;
+        // An orphan is its own parent without being a root.
+        if entry.parent == ino {
+            return None;
+        }
        parts.push(entry.node.name.clone());
        ino = entry.parent;
    }
@@ -6,7 +6,7 @@
 //! invisible; in an in-process remount — which is how the daemon recovers from a
 //! mount going away underneath it — it leaks a whole generation of threads that
 //! keep writing to the database and calling the API on behalf of a mount that no
-//! longer exists (bugs.md B44).
+//! longer exists (`docs/BUGS.md` B44).
 //!
 //! The primitive is deliberately small: a flag plus a condvar. Every loop that
 //! would otherwise call `thread::sleep` calls [`Shutdown::sleep`] instead, which
@@ -0,0 +1,9 @@
+//! The simulation tests of `docs/TESTING.md`: a fake Drive with
+//! the faults the real one has, and the tools to drive daemons against it.
+
+pub(crate) mod daemon;
+pub(crate) mod fake_drive;
+pub(crate) mod model;
+pub(crate) mod rng;
+pub(crate) mod run;
+pub(crate) mod watchdog;
@@ -0,0 +1,445 @@
+//! The reference file system of the simulation (`docs/TESTING.md`,
+//! "Simulation runs", property 1): what each syscall a simulated client makes should
+//! answer, and the tree it should leave, on a POSIX file system.
+//!
+//! A [`Model`] covers one client's own folder; paths are relative to it. The
+//! same type is used for the trees read back from a mount and from Drive.
+
+use std::collections::BTreeMap;
+
+use super::rng::Rng;
+
+/// A tree by path: `None` is a folder, `Some` a file's content.
+pub(crate) type Tree = BTreeMap<String, Option<Vec<u8>>>;
+
+/// One file system call, or the few a program makes in a row.
+#[derive(Clone, Debug)]
+pub(crate) enum FsOp {
+    /// `open(O_CREAT | O_TRUNC)`, write `data`, close.
+    Create {
+        path: String,
+        data: Vec<u8>,
+    },
+    /// Open an existing file, write `data` at `offset` (past the end leaves
+    /// a hole), close.
+    Write {
+        path: String,
+        offset: u64,
+        data: Vec<u8>,
+    },
+    /// Open an existing file and `ftruncate` it to `len`.
+    Truncate {
+        path: String,
+        len: u64,
+    },
+    Mkdir {
+        path: String,
+    },
+    Rename {
+        from: String,
+        to: String,
+    },
+    Unlink {
+        path: String,
+    },
+    /// Open a file, unlink it, append `data`, read it all back, close.
+    UnlinkOpen {
+        path: String,
+        data: Vec<u8>,
+    },
+    Rmdir {
+        path: String,
+    },
+}
+
+impl FsOp {
+    /// The paths the op names, for the log.
+    pub(crate) fn describe(&self) -> String {
+        match self {
+            FsOp::Create { path, data } => format!("create {path} ({} bytes)", data.len()),
+            FsOp::Write { path, offset, data } => {
+                format!("write {path} at {offset} ({} bytes)", data.len())
+            }
+            FsOp::Truncate { path, len } => format!("truncate {path} to {len}"),
+            FsOp::Mkdir { path } => format!("mkdir {path}"),
+            FsOp::Rename { from, to } => format!("rename {from} -> {to}"),
+            FsOp::Unlink { path } => format!("unlink {path}"),
+            FsOp::UnlinkOpen { path, data } => {
+                format!("unlink {path} while open, then append {} bytes", data.len())
+            }
+            FsOp::Rmdir { path } => format!("rmdir {path}"),
+        }
+    }
+}
+
+/// The tree one client should have, and what its syscalls should answer.
+#[derive(Clone, Debug, Default)]
+pub(crate) struct Model {
+    tree: Tree,
+}
+
+/// Names are drawn from small pools, so ops collide: a create over an existing
+/// file, a rename over another, a mkdir of a name that is taken.
+const FILE_NAMES: [&str; 6] = ["a.txt", "b.txt", "c.bin", "d", "e.md", "f.txt"];
+const DIR_NAMES: [&str; 3] = ["x", "y", "z"];
+
+impl Model {
+    pub(crate) fn tree(&self) -> &Tree {
+        &self.tree
+    }
+
+    pub(crate) fn content(&self, path: &str) -> Option<&Vec<u8>> {
+        self.tree.get(path)?.as_ref()
+    }
+
+    /// What `op` should answer on a POSIX file system, applying it on success.
+    pub(crate) fn apply(&mut self, op: &FsOp) -> Result<(), i32> {
+        match op {
+            FsOp::Create { path, data } => {
+                self.check_parent(path)?;
+                match self.tree.get(path) {
+                    Some(None) => Err(libc::EISDIR),
+                    _ => {
+                        self.tree.insert(path.clone(), Some(data.clone()));
+                        Ok(())
+                    }
+                }
+            }
+            FsOp::Write { path, offset, data } => {
+                let content = self.file_mut(path)?;
+                // Writing nothing changes nothing, even past the end.
+                if data.is_empty() {
+                    return Ok(());
+                }
+                let end = *offset as usize + data.len();
+                if content.len() < end {
+                    content.resize(end, 0);
+                }
+                content[*offset as usize..end].copy_from_slice(data);
+                Ok(())
+            }
+            FsOp::Truncate { path, len } => {
+                self.file_mut(path)?.resize(*len as usize, 0);
+                Ok(())
+            }
+            FsOp::Mkdir { path } => {
+                self.check_parent(path)?;
+                if self.tree.contains_key(path) {
+                    return Err(libc::EEXIST);
+                }
+                self.tree.insert(path.clone(), None);
+                Ok(())
+            }
+            FsOp::Rename { from, to } => self.rename(from, to),
+            FsOp::Unlink { path } | FsOp::UnlinkOpen { path, .. } => {
+                self.check_parent(path)?;
+                match self.tree.get(path) {
+                    None => Err(libc::ENOENT),
+                    Some(None) => Err(libc::EISDIR),
+                    Some(Some(_)) => {
+                        self.tree.remove(path);
+                        Ok(())
+                    }
+                }
+            }
+            FsOp::Rmdir { path } => {
+                self.check_parent(path)?;
+                match self.tree.get(path) {
+                    None => Err(libc::ENOENT),
+                    Some(Some(_)) => Err(libc::ENOTDIR),
+                    Some(None) if self.has_children(path) => Err(libc::ENOTEMPTY),
+                    Some(None) => {
+                        self.tree.remove(path);
+                        Ok(())
+                    }
+                }
+            }
+        }
+    }
+
+    fn rename(&mut self, from: &str, to: &str) -> Result<(), i32> {
+        self.check_parent(from)?;
+        let Some(moving) = self.tree.get(from).cloned() else {
+            return Err(libc::ENOENT);
+        };
+        self.check_parent(to)?;
+        if from == to {
+            return Ok(());
+        }
+        if is_below(to, from) {
+            return Err(libc::EINVAL);
+        }
+        match (&moving, self.tree.get(to)) {
+            (None, Some(Some(_))) => return Err(libc::ENOTDIR),
+            (Some(_), Some(None)) => return Err(libc::EISDIR),
+            (None, Some(None)) if self.has_children(to) => return Err(libc::ENOTEMPTY),
+            _ => {}
+        }
+        let below: Vec<(String, Option<Vec<u8>>)> = self
+            .tree
+            .iter()
+            .filter(|(path, _)| is_below(path, from))
+            .map(|(path, entry)| (path.clone(), entry.clone()))
+            .collect();
+        self.tree.remove(from);
+        self.tree.insert(to.to_owned(), moving);
+        for (path, entry) in below {
+            self.tree.remove(&path);
+            self.tree
+                .insert(format!("{to}{}", &path[from.len()..]), entry);
+        }
+        Ok(())
+    }
+
+    fn file_mut(&mut self, path: &str) -> Result<&mut Vec<u8>, i32> {
+        self.check_parent(path)?;
+        match self.tree.get_mut(path) {
+            None => Err(libc::ENOENT),
+            Some(None) => Err(libc::EISDIR),
+            Some(Some(content)) => Ok(content),
+        }
+    }
+
+    fn check_parent(&self, path: &str) -> Result<(), i32> {
+        let mut at = String::new();
+        let mut names = path.split('/').peekable();
+        while let Some(name) = names.next() {
+            if names.peek().is_none() {
+                break;
+            }
+            if !at.is_empty() {
+                at.push('/');
+            }
+            at.push_str(name);
+            match self.tree.get(&at) {
+                None => return Err(libc::ENOENT),
+                Some(Some(_)) => return Err(libc::ENOTDIR),
+                Some(None) => {}
+            }
+        }
+        Ok(())
+    }
+
+    fn has_children(&self, path: &str) -> bool {
+        self.tree.keys().any(|other| is_below(other, path))
+    }
+
+    pub(crate) fn files(&self) -> Vec<&String> {
+        self.tree
+            .iter()
+            .filter(|(_, entry)| entry.is_some())
+            .map(|(path, _)| path)
+            .collect()
+    }
+
+    /// Folders, the client's own root (`""`) first.
+    fn dirs(&self) -> Vec<String> {
+        std::iter::once(String::new())
+            .chain(
+                self.tree
+                    .iter()
+                    .filter(|(_, entry)| entry.is_none())
+                    .map(|(path, _)| path.clone()),
+            )
+            .collect()
+    }
+
+    /// A random op, mostly one that should succeed.
+    pub(crate) fn next_op(&self, rng: &mut Rng) -> FsOp {
+        let dirs = self.dirs();
+        let files = self.files();
+        let in_dir = |rng: &mut Rng, names: &[&str]| {
+            let parent = rng.pick(&dirs).expect("the root is always there");
+            join(parent, rng.pick(names).expect("names"))
+        };
+        let a_file = |rng: &mut Rng| rng.pick(&files).map(|path| (*path).clone());
+        let roll = rng.below(100);
+        let op = match roll {
+            0..30 => Some(FsOp::Create {
+                path: in_dir(rng, &FILE_NAMES),
+                data: data(rng),
+            }),
+            30..45 => a_file(rng).map(|path| {
+                let len = self.content(&path).map_or(0, Vec::len) as u64;
+                FsOp::Write {
+                    offset: rng.below(len + 8),
+                    path,
+                    data: data(rng),
+                }
+            }),
+            45..50 => a_file(rng).map(|path| FsOp::Truncate {
+                len: rng.below(32),
+                path,
+            }),
+            50..60 => Some(FsOp::Mkdir {
+                path: in_dir(rng, &DIR_NAMES),
+            }),
+            // A rename in place, over another file as often as not.
+            60..72 => a_file(rng).map(|from| FsOp::Rename {
+                to: join(parent_of(&from), rng.pick(&FILE_NAMES).expect("names")),
+                from,
+            }),
+            // A move to another folder, renamed or not.
+            72..82 => a_file(rng).map(|from| {
+                let name = if rng.chance(0.5) {
+                    name_of(&from)
+                } else {
+                    rng.pick(&FILE_NAMES).expect("names")
+                };
+                let parent = rng.pick(&dirs).expect("the root is always there");
+                FsOp::Rename {
+                    to: join(parent, name),
+                    from,
+                }
+            }),
+            // A folder renamed or moved, with what is in it.
+            82..86 => {
+                let from = rng.pick(&dirs[1..]).cloned();
+                from.map(|from| FsOp::Rename {
+                    to: in_dir(rng, &DIR_NAMES),
+                    from,
+                })
+            }
+            86..94 => a_file(rng).map(|path| FsOp::Unlink { path }),
+            94..97 => a_file(rng).map(|path| FsOp::UnlinkOpen {
+                path,
+                data: data(rng),
+            }),
+            _ => rng
+                .pick(&dirs[1..])
+                .cloned()
+                .map(|path| FsOp::Rmdir { path }),
+        };
+        op.unwrap_or_else(|| FsOp::Create {
+            path: in_dir(rng, &FILE_NAMES),
+            data: data(rng),
+        })
+    }
+}
+
+/// Content for a write: short and recognisable, now and then empty.
+pub(crate) fn data(rng: &mut Rng) -> Vec<u8> {
+    let len = if rng.chance(0.1) {
+        0
+    } else {
+        rng.between(1, 48)
+    };
+    let tag = rng.next_u64();
+    (0..len).map(|i| b'a' + ((tag + i) % 26) as u8).collect()
+}
+
+pub(crate) fn join(parent: &str, name: &str) -> String {
+    if parent.is_empty() {
+        name.to_owned()
+    } else {
+        format!("{parent}/{name}")
+    }
+}
+
+pub(crate) fn parent_of(path: &str) -> &str {
+    path.rsplit_once('/').map_or("", |(parent, _)| parent)
+}
+
+pub(crate) fn name_of(path: &str) -> &str {
+    path.rsplit_once('/').map_or(path, |(_, name)| name)
+}
+
+fn is_below(path: &str, ancestor: &str) -> bool {
+    path.len() > ancestor.len() + 1
+        && path.starts_with(ancestor)
+        && path.as_bytes()[ancestor.len()] == b'/'
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn create(path: &str, data: &[u8]) -> FsOp {
+        FsOp::Create {
+            path: path.into(),
+            data: data.to_vec(),
+        }
+    }
+
+    #[test]
+    fn a_rename_over_a_file_replaces_it_and_a_folder_moves_with_its_contents() {
+        let mut model = Model::default();
+        model.apply(&FsOp::Mkdir { path: "x".into() }).unwrap();
+        model.apply(&create("x/a", b"1")).unwrap();
+        model.apply(&create("b", b"2")).unwrap();
+        model
+            .apply(&FsOp::Rename {
+                from: "b".into(),
+                to: "x/a".into(),
+            })
+            .unwrap();
+        assert_eq!(model.content("x/a"), Some(&b"2".to_vec()));
+        model
+            .apply(&FsOp::Rename {
+                from: "x".into(),
+                to: "y".into(),
+            })
+            .unwrap();
+        assert_eq!(model.tree().keys().collect::<Vec<_>>(), vec!["y", "y/a"]);
+    }
+
+    #[test]
+    fn calls_fail_the_way_posix_says() {
+        let mut model = Model::default();
+        model.apply(&FsOp::Mkdir { path: "x".into() }).unwrap();
+        model.apply(&create("x/a", b"1")).unwrap();
+        assert_eq!(
+            model.apply(&FsOp::Mkdir { path: "x".into() }),
+            Err(libc::EEXIST)
+        );
+        assert_eq!(model.apply(&create("x", b"")), Err(libc::EISDIR));
+        assert_eq!(model.apply(&create("x/a/b", b"")), Err(libc::ENOTDIR));
+        assert_eq!(model.apply(&create("q/a", b"")), Err(libc::ENOENT));
+        assert_eq!(
+            model.apply(&FsOp::Rmdir { path: "x".into() }),
+            Err(libc::ENOTEMPTY)
+        );
+        assert_eq!(
+            model.apply(&FsOp::Unlink { path: "x".into() }),
+            Err(libc::EISDIR)
+        );
+        let into_itself = FsOp::Rename {
+            from: "x".into(),
+            to: "x/y".into(),
+        };
+        assert_eq!(model.apply(&into_itself), Err(libc::EINVAL));
+    }
+
+    #[test]
+    fn a_write_past_the_end_leaves_a_hole() {
+        let mut model = Model::default();
+        model.apply(&create("a", b"ab")).unwrap();
+        let write = FsOp::Write {
+            path: "a".into(),
+            offset: 4,
+            data: b"z".to_vec(),
+        };
+        model.apply(&write).unwrap();
+        assert_eq!(model.content("a"), Some(&b"ab\0\0z".to_vec()));
+        let nothing = FsOp::Write {
+            path: "a".into(),
+            offset: 9,
+            data: Vec::new(),
+        };
+        model.apply(&nothing).unwrap();
+        assert_eq!(model.content("a"), Some(&b"ab\0\0z".to_vec()));
+    }
+
+    #[test]
+    fn generated_ops_mostly_succeed() {
+        let mut rng = Rng::new(9);
+        let mut model = Model::default();
+        let ok = (0..500)
+            .filter(|_| {
+                let op = model.next_op(&mut rng);
+                model.apply(&op).is_ok()
+            })
+            .count();
+        assert!(ok > 350, "{ok} of 500 succeeded");
+    }
+}
@@ -0,0 +1,79 @@
+//! A small seeded random number generator, so a failing simulation is a seed
+//! that can be replayed. SplitMix64: fast, good enough for choosing operations
+//! and faults, and no dependency.
+
+#[derive(Clone, Debug)]
+pub(crate) struct Rng(u64);
+
+impl Rng {
+    pub(crate) fn new(seed: u64) -> Self {
+        Self(seed)
+    }
+
+    pub(crate) fn next_u64(&mut self) -> u64 {
+        self.0 = self.0.wrapping_add(0x9E37_79B9_7F4A_7C15);
+        let mut z = self.0;
+        z = (z ^ (z >> 30)).wrapping_mul(0xBF58_476D_1CE4_E5B9);
+        z = (z ^ (z >> 27)).wrapping_mul(0x94D0_49BB_1331_11EB);
+        z ^ (z >> 31)
+    }
+
+    /// A value in `0..n`; `0` when `n` is `0`.
+    pub(crate) fn below(&mut self, n: u64) -> u64 {
+        if n == 0 { 0 } else { self.next_u64() % n }
+    }
+
+    /// A value in `lo..=hi`.
+    pub(crate) fn between(&mut self, lo: u64, hi: u64) -> u64 {
+        lo + self.below(hi.saturating_sub(lo) + 1)
+    }
+
+    /// True with probability `p`.
+    pub(crate) fn chance(&mut self, p: f64) -> bool {
+        p > 0.0 && (self.next_u64() >> 11) as f64 / (1u64 << 53) as f64 <= p
+    }
+
+    pub(crate) fn pick<'a, T>(&mut self, items: &'a [T]) -> Option<&'a T> {
+        items.get(self.below(items.len() as u64) as usize)
+    }
+
+    /// A child generator, so one consumer's draws do not shift another's.
+    pub(crate) fn fork(&mut self) -> Self {
+        Self::new(self.next_u64())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Rng;
+
+    #[test]
+    fn a_seed_replays_the_same_sequence() {
+        let (mut a, mut b) = (Rng::new(7), Rng::new(7));
+        for _ in 0..100 {
+            assert_eq!(a.next_u64(), b.next_u64());
+        }
+        assert_ne!(Rng::new(7).next_u64(), Rng::new(8).next_u64());
+    }
+
+    #[test]
+    fn bounded_draws_stay_in_range() {
+        let mut rng = Rng::new(1);
+        for _ in 0..1000 {
+            assert!(rng.below(5) < 5);
+            assert!((3..=9).contains(&rng.between(3, 9)));
+        }
+        assert_eq!(rng.below(0), 0);
+        assert!(!rng.chance(0.0));
+        assert!(rng.chance(1.0));
+        assert!([1, 2, 3].contains(rng.pick(&[1, 2, 3]).unwrap()));
+        assert_eq!(rng.pick::<u8>(&[]), None);
+    }
+
+    #[test]
+    fn a_fork_draws_apart_from_its_parent() {
+        let mut parent = Rng::new(3);
+        let mut child = parent.fork();
+        assert_ne!(parent.next_u64(), child.next_u64());
+    }
+}
@@ -0,0 +1,766 @@
+//! The simulation runs described in `docs/TESTING.md`.
+//!
+//! A run starts one or more daemons on a shared [`FakeDrive`], each owning a
+//! folder `c<n>` that only it writes, so there is one writer per file. A seed
+//! draws a sequence of steps: syscalls through a client's mount, the link of a
+//! client going down or up, a client restarting, a pause, a settle (every
+//! queue must drain within a budget), or a file deleted while the drain holds
+//! a write to it. Every syscall is checked against the
+//! client's [`Model`] as it happens. After the sequence every link comes up
+//! and the run checks:
+//!
+//! 1. **No loss** and **POSIX**: Drive's copy of each client's folder is what
+//!    its model says.
+//! 2. **No false conflicts**: no conflict copy anywhere, and the drain never
+//!    takes a client's own delete for another device's.
+//! 3. **Convergence**: each mount shows Drive's tree.
+//! 4. **Liveness**: no syscall took longer than its budget, settles drained in
+//!    theirs, and every queue drained once the links were up. A call that
+//!    never returns is caught by the [`Watchdog`], which keeps the stacks.
+//!
+//! A restart here is a stop and a start: the next run finds what the last
+//! one wrote down, but in-flight work is let finish rather than cut. A kill
+//! at an arbitrary point needs the daemon in a process of its own.
+//!
+//! Any of these fails the seed. No open bug is tolerated: the matchers that
+//! counted the ones still open instead (B125 to B134) went once a run on
+//! 812eb3d passed every profile without them.
+//!
+//! The runs are ignored by default because they mount FUSE; run them with
+//! `cargo test -p pdfs-fuse --lib sim::run -- --ignored --test-threads=1`.
+//! `PDFS_SIM_SEEDS=n` sets how many seeds each runs, `PDFS_SIM_SEED=s` replays
+//! one, and `RUST_LOG=pdfs_fuse=debug` with `--nocapture` shows the daemons'
+//! logs.
+
+use std::fs::OpenOptions;
+use std::io::{self, Read, Seek, SeekFrom, Write};
+use std::path::{Path, PathBuf};
+use std::time::{Duration, Instant};
+
+use super::daemon::{Daemon, scratch, take_logged, wait_until};
+use super::fake_drive::{Entry, FakeDrive, Faults};
+use super::model::{FsOp, Model, Tree, data, join};
+use super::rng::Rng;
+use super::watchdog::Watchdog;
+
+/// What a run looks like.
+pub(crate) struct Profile {
+    pub(crate) name: &'static str,
+    pub(crate) clients: usize,
+    pub(crate) steps: usize,
+    pub(crate) faults: fn() -> Faults,
+    /// Whether links go down and come back during the sequence.
+    pub(crate) link_flaps: bool,
+    pub(crate) restarts: bool,
+    /// Whether files are deleted while the drain holds a write to them.
+    pub(crate) deletes_mid_upload: bool,
+    /// How long a settle may take; `None` leaves settles out.
+    pub(crate) settle_budget: Option<Duration>,
+    /// How long one syscall may take.
+    pub(crate) syscall_budget: Duration,
+    /// How long the queues may take to drain at the end.
+    pub(crate) drain_budget: Duration,
+}
+
+/// How long the mounts may take to show Drive's tree at the end: one event
+/// poll (`POLL_INTERVAL`) and change.
+const CONVERGE_BUDGET: Duration = Duration::from_secs(30);
+
+/// How long the drain may take to pick up a write: its debounce, and then
+/// some.
+const PICKUP_BUDGET: Duration = Duration::from_secs(8);
+
+/// Steps shown before a failure. All of them are written to `steps.log` in
+/// the state the failure keeps.
+const LOG_TAIL: usize = 40;
+
+/// How long past its own budget a step, or the checks after the last one, may
+/// run before the watchdog takes it for hung. Longer than a restart may wait
+/// for the last run and the mount.
+const STALL: Duration = Duration::from_secs(120);
+
+struct Client {
+    daemon: Option<Daemon>,
+    model: Model,
+    online: bool,
+}
+
+impl Client {
+    fn daemon(&self) -> &Daemon {
+        self.daemon
+            .as_ref()
+            .expect("a client always has a daemon between steps")
+    }
+
+    fn root(&self, index: usize) -> PathBuf {
+        self.daemon().mountpoint.join(owned_folder(index))
+    }
+}
+
+struct Run {
+    seed: u64,
+    profile: &'static Profile,
+    drive: std::sync::Arc<FakeDrive>,
+    clients: Vec<Client>,
+    log: Vec<String>,
+    started: Instant,
+    /// What the daemons logged at `INFO` and above so far.
+    logged: Vec<String>,
+    watchdog: Watchdog,
+}
+
+/// Run `profile` on `seed`. It answers a report of what went wrong, if
+/// anything did.
+pub(crate) fn run(seed: u64, profile: &'static Profile) -> Result<(), String> {
+    let dir = scratch(&format!("{}-{seed}", profile.name));
+    let mut rng = Rng::new(seed);
+    let drive = FakeDrive::new();
+    let mut run = Run {
+        seed,
+        profile,
+        drive: drive.clone(),
+        clients: Vec::new(),
+        log: Vec::new(),
+        started: Instant::now(),
+        logged: Vec::new(),
+        watchdog: Watchdog::new(&dir),
+    };
+    let outcome = run.execute(&dir, &mut rng);
+    run.watchdog.stop();
+    // A hang is what failed, whatever the aborted call answered.
+    let outcome = match run.watchdog.fired() {
+        Some(hung) => Err(format!("liveness: {}", hung.what)),
+        None => outcome,
+    };
+    for client in &mut run.clients {
+        if let Some(daemon) = client.daemon.take() {
+            let _ = daemon.stop();
+        }
+    }
+    match outcome {
+        Ok(()) => {
+            let _ = std::fs::remove_dir_all(&dir);
+            Ok(())
+        }
+        Err(failure) => Err(run.report(&failure, &dir)),
+    }
+}
+
+impl Run {
+    fn execute(&mut self, dir: &Path, rng: &mut Rng) -> Result<(), String> {
+        for index in 0..self.profile.clients {
+            let client = self.drive.client(rng.next_u64(), (self.profile.faults)());
+            let daemon = Daemon::start(&dir.join(format!("client{index}")), client)
+                .map_err(|error| format!("client {index} did not mount: {error}"))?;
+            let folder = daemon.mountpoint.join(owned_folder(index));
+            std::fs::create_dir(&folder)
+                .map_err(|error| format!("client {index}: mkdir {}: {error}", folder.display()))?;
+            self.clients.push(Client {
+                daemon: Some(daemon),
+                model: Model::default(),
+                online: true,
+            });
+        }
+        for step in 0..self.profile.steps {
+            let _watching = self.watchdog.arm(self.step_limit(), format!("step {step}"));
+            self.step(rng)?;
+        }
+        let _watching = self.watchdog.arm(
+            self.profile.drain_budget + STALL,
+            "the checks after the last step",
+        );
+        self.finish()
+    }
+
+    /// How long a step may run before the watchdog takes it for hung.
+    fn step_limit(&self) -> Duration {
+        let budget = self.profile.settle_budget.unwrap_or_default();
+        budget.max(self.profile.syscall_budget) + STALL
+    }
+
+    fn step(&mut self, rng: &mut Rng) -> Result<(), String> {
+        let index = rng.below(self.clients.len() as u64) as usize;
+        let roll = rng.below(100);
+        match roll {
+            0..4 if self.profile.link_flaps => {
+                let client = &mut self.clients[index];
+                client.online = !client.online;
+                client.daemon().client.set_online(client.online);
+                let state = if client.online { "up" } else { "down" };
+                self.note(format!("client {index}: link {state}"));
+            }
+            4..6 if self.profile.restarts => {
+                self.note(format!("client {index}: restart"));
+                let daemon = self.clients[index].daemon.take().expect("daemon");
+                let daemon = daemon
+                    .restart()
+                    .map_err(|error| format!("client {index} did not come back: {error}"))?;
+                self.clients[index].daemon = Some(daemon);
+            }
+            6..12 => {
+                let ms = rng.below(400);
+                self.note(format!("pause {ms} ms"));
+                std::thread::sleep(Duration::from_millis(ms));
+            }
+            12..15 => {
+                if let Some(budget) = self.profile.settle_budget
+                    && self.clients.iter().all(|client| client.online)
+                {
+                    self.settle(budget)?;
+                }
+            }
+            15..25 if self.profile.deletes_mid_upload => self.delete_mid_upload(index, rng)?,
+            _ => {
+                let op = self.clients[index].model.next_op(rng);
+                self.syscall(index, op)?;
+            }
+        }
+        Ok(())
+    }
+
+    /// Wait until every queue is empty and Drive holds what the models say.
+    fn settle(&mut self, budget: Duration) -> Result<(), String> {
+        self.note("settle".into());
+        let start = Instant::now();
+        // What the drain logs meanwhile is what explains a known bug's damage.
+        if !wait_until(budget, || {
+            self.logged.extend(take_logged());
+            self.landed()
+        }) {
+            return Err(format!(
+                "liveness: the queues did not drain within {budget:?}\n{}",
+                self.difference()
+            ));
+        }
+        self.note(format!("settled in {:?}", start.elapsed()));
+        Ok(())
+    }
+
+    /// Write a file Drive holds and delete it once the drain has picked the
+    /// write up. The drain's read of the node is held until the delete has
+    /// landed and a read shows it, so the drain finds the file trashed while
+    /// it holds a write that is no longer queued (B105). Half the time the
+    /// file is made again meanwhile, which queues a write under the op id the
+    /// delete freed (B133).
+    fn delete_mid_upload(&mut self, index: usize, rng: &mut Rng) -> Result<(), String> {
+        let file = rng
+            .pick(&self.clients[index].model.files())
+            .map(|path| (*path).clone());
+        let (Some(path), Some(budget), true) = (
+            file,
+            self.profile.settle_budget,
+            self.clients.iter().all(|client| client.online),
+        ) else {
+            let op = self.clients[index].model.next_op(rng);
+            return self.syscall(index, op);
+        };
+        self.settle(budget)?;
+        let Some(uid) = self.drive.lookup(&join(&owned_folder(index), &path)) else {
+            return Err(format!(
+                "no loss: client {index}'s {path} is not on Drive after a settle"
+            ));
+        };
+        let held = self.clients[index].daemon().client.hold_next_read(&uid);
+        self.note(format!("client {index}: hold the next read of {path}"));
+        let mut bytes = data(rng);
+        bytes.push(b'.');
+        self.syscall(
+            index,
+            FsOp::Write {
+                path: path.clone(),
+                offset: 0,
+                data: bytes,
+            },
+        )?;
+        if !wait_until(PICKUP_BUDGET, || held.reached()) {
+            self.note(format!("client {index}: nothing read {path} back"));
+            return Ok(());
+        }
+        self.syscall(index, FsOp::Unlink { path: path.clone() })?;
+        if rng.chance(0.5) {
+            self.syscall(
+                index,
+                FsOp::Create {
+                    path: path.clone(),
+                    data: data(rng),
+                },
+            )?;
+        }
+        let faults = (self.profile.faults)();
+        let latency = Duration::from_millis(faults.latency_ms.1);
+        std::thread::sleep(faults.listing_lag + latency);
+        drop(held);
+        self.note(format!("client {index}: the read of {path} goes on"));
+        // Nothing else is queued before the drain has answered.
+        std::thread::sleep(2 * latency + Duration::from_millis(50));
+        Ok(())
+    }
+
+    fn syscall(&mut self, index: usize, op: FsOp) -> Result<(), String> {
+        let client = &mut self.clients[index];
+        let root = client.root(index);
+        let before = client.model.content(target(&op)).cloned();
+        let expected = client.model.apply(&op);
+        self.logged.extend(take_logged());
+        let start = Instant::now();
+        let actual = perform(&root, &op, before.as_deref());
+        let took = start.elapsed();
+        self.note(format!(
+            "client {index}: {} = {} in {took:?}",
+            op.describe(),
+            outcome(&actual)
+        ));
+        let actual = actual?;
+        self.logged.extend(take_logged());
+        if actual != expected {
+            return Err(format!(
+                "posix: client {index}: {} answered {}, expected {}",
+                op.describe(),
+                errno(actual),
+                errno(expected)
+            ));
+        }
+        if took > self.profile.syscall_budget {
+            return Err(format!(
+                "liveness: client {index}: {} took {took:?}, over {:?}",
+                op.describe(),
+                self.profile.syscall_budget
+            ));
+        }
+        Ok(())
+    }
+
+    fn finish(&mut self) -> Result<(), String> {
+        for client in &mut self.clients {
+            client.online = true;
+            client.daemon().client.set_online(true);
+        }
+        self.note("every link up; waiting for the queues".into());
+        if !wait_until(self.profile.drain_budget, || {
+            self.logged.extend(take_logged());
+            self.landed()
+        }) {
+            return Err(format!(
+                "no loss: Drive does not hold what the clients wrote, {:?} after the links came up\n{}",
+                self.profile.drain_budget,
+                self.difference()
+            ));
+        }
+        // Each client's folder is its own, so a file of it gone from Drive was
+        // deleted by the client.
+        if let Some(line) = self.logged.iter().find(|line| is_own_delete_kept(line)) {
+            return Err(format!(
+                "no false conflicts: the drain took a client's own delete for another device's: {line}"
+            ));
+        }
+        let drive = self.drive_tree();
+        let conflicts: Vec<String> = drive
+            .into_keys()
+            .filter(|path| is_conflict_copy(path))
+            .collect();
+        if !conflicts.is_empty() {
+            return Err(format!("no false conflicts: {conflicts:?}"));
+        }
+        for index in 0..self.clients.len() {
+            let mut last = Tree::new();
+            let converged = wait_until(CONVERGE_BUDGET, || {
+                last = read_tree(&self.clients[index].daemon().mountpoint);
+                last == self.drive_tree()
+            });
+            if !converged {
+                return Err(format!(
+                    "convergence: client {index}'s mount differs from Drive\n{}",
+                    diff(&last, &self.drive_tree(), "mount", "Drive")
+                ));
+            }
+        }
+        Ok(())
+    }
+
+    /// Whether every client's queue is empty and Drive holds what its model
+    /// says.
+    fn landed(&self) -> bool {
+        let drive = self.drive_tree();
+        self.clients.iter().enumerate().all(|(index, client)| {
+            client
+                .daemon()
+                .pending()
+                .is_ok_and(|items| items.is_empty())
+                && subtree(&drive, &owned_folder(index)) == *client.model.tree()
+        })
+    }
+
+    fn difference(&self) -> String {
+        let drive = self.drive_tree();
+        let mut out = String::new();
+        for (index, client) in self.clients.iter().enumerate() {
+            let pending = client.daemon().pending().unwrap_or_default();
+            for item in pending {
+                out.push_str(&format!(
+                    "  client {index} still owes: {} {} (attempts {}, last error {:?})\n",
+                    item.kind, item.path, item.attempts, item.last_error
+                ));
+            }
+            out.push_str(&diff(
+                client.model.tree(),
+                &subtree(&drive, &owned_folder(index)),
+                &format!("client {index}'s model"),
+                "Drive",
+            ));
+        }
+        out
+    }
+
+    fn drive_tree(&self) -> Tree {
+        self.drive
+            .tree()
+            .into_iter()
+            .map(|(path, entry)| {
+                let content = match entry {
+                    Entry::Folder => None,
+                    Entry::File(content) => Some(content.as_ref().clone()),
+                };
+                (path, content)
+            })
+            .collect()
+    }
+
+    fn note(&mut self, line: String) {
+        let line = format!("{:>8.3}s {line}", self.started.elapsed().as_secs_f64());
+        self.log.push(line);
+    }
+
+    fn report(&self, failure: &str, dir: &Path) -> String {
+        let _ = std::fs::write(dir.join("steps.log"), self.log.join("\n") + "\n");
+        let tail = &self.log[self.log.len().saturating_sub(LOG_TAIL)..];
+        format!(
+            "{} seed {} failed: {failure}\nreplay with PDFS_SIM_SEED={}; state kept in {}\nlast steps:\n{}",
+            self.profile.name,
+            self.seed,
+            self.seed,
+            dir.display(),
+            tail.join("\n")
+        )
+    }
+}
+
+/// Make `op` under `root`. The outer error is a check that failed on the
+/// way (the content an open file reads back), the inner one the errno.
+fn perform(root: &Path, op: &FsOp, before: Option<&[u8]>) -> Result<Result<(), i32>, String> {
+    let at = |path: &str| root.join(path);
+    let result: io::Result<()> = match op {
+        FsOp::Create { path, data } => std::fs::write(at(path), data),
+        FsOp::Write { path, offset, data } => OpenOptions::new()
+            .write(true)
+            .open(at(path))
+            .and_then(|mut file| {
+                file.seek(SeekFrom::Start(*offset))?;
+                file.write_all(data)
+            }),
+        FsOp::Truncate { path, len } => OpenOptions::new()
+            .write(true)
+            .open(at(path))
+            .and_then(|file| file.set_len(*len)),
+        FsOp::Mkdir { path } => std::fs::create_dir(at(path)),
+        FsOp::Rename { from, to } => std::fs::rename(at(from), at(to)),
+        FsOp::Unlink { path } => std::fs::remove_file(at(path)),
+        FsOp::Rmdir { path } => std::fs::remove_dir(at(path)),
+        FsOp::UnlinkOpen { path, data } => {
+            let mut read = Vec::new();
+            let result = OpenOptions::new()
+                .read(true)
+                .write(true)
+                .open(at(path))
+                .and_then(|mut file| {
+                    std::fs::remove_file(at(path))?;
+                    file.seek(SeekFrom::End(0))?;
+                    file.write_all(data)?;
+                    file.seek(SeekFrom::Start(0))?;
+                    file.read_to_end(&mut read).map(|_| ())
+                });
+            if result.is_ok() {
+                let expected = [before.unwrap_or_default(), data].concat();
+                if read != expected {
+                    return Err(format!(
+                        "posix: {} read back {:?}, expected {:?}",
+                        op.describe(),
+                        String::from_utf8_lossy(&read),
+                        String::from_utf8_lossy(&expected)
+                    ));
+                }
+            }
+            result
+        }
+    };
+    Ok(result.map_err(|error| error.raw_os_error().unwrap_or(libc::EIO)))
+}
+
+fn target(op: &FsOp) -> &str {
+    match op {
+        FsOp::Create { path, .. }
+        | FsOp::Write { path, .. }
+        | FsOp::Truncate { path, .. }
+        | FsOp::Mkdir { path }
+        | FsOp::Unlink { path }
+        | FsOp::UnlinkOpen { path, .. }
+        | FsOp::Rmdir { path } => path,
+        FsOp::Rename { from, .. } => from,
+    }
+}
+
+/// The tree a mount shows, read through it, without the folders it makes up
+/// that are not on Drive.
+fn read_tree(mountpoint: &Path) -> Tree {
+    fn walk(dir: &Path, prefix: &str, tree: &mut Tree) {
+        let Ok(entries) = std::fs::read_dir(dir) else {
+            return;
+        };
+        for entry in entries.flatten() {
+            let name = entry.file_name().to_string_lossy().into_owned();
+            if prefix.is_empty() && name == crate::r#virtual::SHARED_WITH_ME_BASE {
+                continue;
+            }
+            let path = super::model::join(prefix, &name);
+            if entry.file_type().is_ok_and(|kind| kind.is_dir()) {
+                tree.insert(path.clone(), None);
+                walk(&entry.path(), &path, tree);
+            } else {
+                tree.insert(path, std::fs::read(entry.path()).ok());
+            }
+        }
+    }
+    let mut tree = Tree::new();
+    walk(mountpoint, "", &mut tree);
+    tree
+}
+
+/// The part of `tree` below `folder`, relative to it.
+fn subtree(tree: &Tree, folder: &str) -> Tree {
+    let prefix = format!("{folder}/");
+    tree.iter()
+        .filter_map(|(path, entry)| Some((path.strip_prefix(&prefix)?.to_owned(), entry.clone())))
+        .collect()
+}
+
+fn owned_folder(index: usize) -> String {
+    format!("c{index}")
+}
+
+/// Whether `line` is the drain keeping a queued write as a conflict copy
+/// because Drive no longer holds the file, or holds it in the trash.
+fn is_own_delete_kept(line: &str) -> bool {
+    line.starts_with("queued write conflicts; keeping a conflict copy")
+        && (line.contains(" reason=\"the file was trashed remotely\"")
+            || line.contains(" reason=\"the file no longer exists remotely\""))
+}
+
+fn is_conflict_copy(path: &str) -> bool {
+    path.split('/')
+        .any(|name| name.contains("(sync-conflict") || name.starts_with("recovered-"))
+}
+
+fn diff(left: &Tree, right: &Tree, left_name: &str, right_name: &str) -> String {
+    let show = |entry: &Option<Vec<u8>>| match entry {
+        None => "folder".to_owned(),
+        Some(content) => format!("{:?}", String::from_utf8_lossy(content)),
+    };
+    let mut out = String::new();
+    for (path, entry) in left {
+        match right.get(path) {
+            None => out.push_str(&format!(
+                "  {path}: only in {left_name} ({})\n",
+                show(entry)
+            )),
+            Some(other) if other != entry => out.push_str(&format!(
+                "  {path}: {left_name} has {}, {right_name} has {}\n",
+                show(entry),
+                show(other)
+            )),
+            Some(_) => {}
+        }
+    }
+    for (path, entry) in right {
+        if !left.contains_key(path) {
+            out.push_str(&format!(
+                "  {path}: only in {right_name} ({})\n",
+                show(entry)
+            ));
+        }
+    }
+    out
+}
+
+fn errno(outcome: Result<(), i32>) -> String {
+    match outcome {
+        Ok(()) => "ok".into(),
+        Err(code) => io::Error::from_raw_os_error(code).to_string(),
+    }
+}
+
+fn outcome(actual: &Result<Result<(), i32>, String>) -> String {
+    match actual {
+        Ok(result) => errno(*result),
+        Err(check) => check.clone(),
+    }
+}
+
+/// Run `profile` over the seeds the environment asks for: `PDFS_SIM_SEED`
+/// alone, or `PDFS_SIM_SEEDS` of them (default `default_seeds`) from 1.
+pub(crate) fn run_seeds(profile: &'static Profile, default_seeds: u64) {
+    let seeds: Vec<u64> = match std::env::var("PDFS_SIM_SEED") {
+        Ok(seed) => vec![seed.parse().expect("PDFS_SIM_SEED is a number")],
+        Err(_) => {
+            let count = std::env::var("PDFS_SIM_SEEDS")
+                .ok()
+                .and_then(|count| count.parse().ok())
+                .unwrap_or(default_seeds);
+            (1..=count).collect()
+        }
+    };
+    let failures: Vec<String> = seeds
+        .into_iter()
+        .filter_map(|seed| run(seed, profile).err())
+        .collect();
+    assert!(failures.is_empty(), "\n{}", failures.join("\n\n"));
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    static ONE_CLIENT_LAN: Profile = Profile {
+        name: "one-client-lan",
+        clients: 1,
+        steps: 80,
+        faults: Faults::lan,
+        link_flaps: false,
+        restarts: false,
+        deletes_mid_upload: false,
+        settle_budget: Some(Duration::from_secs(4)),
+        syscall_budget: Duration::from_secs(2),
+        drain_budget: Duration::from_secs(20),
+    };
+
+    static ONE_CLIENT_DELETES: Profile = Profile {
+        name: "one-client-deletes",
+        clients: 1,
+        steps: 30,
+        faults: Faults::lan,
+        link_flaps: false,
+        restarts: false,
+        deletes_mid_upload: true,
+        settle_budget: Some(Duration::from_secs(4)),
+        syscall_budget: Duration::from_secs(2),
+        drain_budget: Duration::from_secs(20),
+    };
+
+    static ONE_CLIENT_ECHOES: Profile = Profile {
+        name: "one-client-echoes",
+        clients: 1,
+        steps: 60,
+        faults: Faults::echoes,
+        link_flaps: false,
+        restarts: false,
+        deletes_mid_upload: false,
+        settle_budget: Some(Duration::from_secs(6)),
+        syscall_budget: Duration::from_secs(2),
+        drain_budget: Duration::from_secs(20),
+    };
+
+    static ONE_CLIENT_FLAKY: Profile = Profile {
+        name: "one-client-flaky",
+        clients: 1,
+        steps: 80,
+        faults: Faults::wifi,
+        link_flaps: true,
+        restarts: true,
+        deletes_mid_upload: false,
+        settle_budget: None,
+        syscall_budget: Duration::from_secs(10),
+        drain_budget: Duration::from_secs(120),
+    };
+
+    /// Wi-Fi's latency, lag and lost replies without the outages: the queue
+    /// has to drain within a settle, not merely by the end.
+    static ONE_CLIENT_WIFI: Profile = Profile {
+        name: "one-client-wifi",
+        clients: 1,
+        steps: 80,
+        faults: Faults::wifi,
+        link_flaps: false,
+        restarts: false,
+        deletes_mid_upload: false,
+        settle_budget: Some(Duration::from_secs(30)),
+        syscall_budget: Duration::from_secs(10),
+        drain_budget: Duration::from_secs(120),
+    };
+
+    static THREE_CLIENTS: Profile = Profile {
+        name: "three-clients",
+        clients: 3,
+        steps: 90,
+        faults: Faults::lan,
+        link_flaps: true,
+        restarts: true,
+        deletes_mid_upload: false,
+        settle_budget: Some(Duration::from_secs(4)),
+        syscall_budget: Duration::from_secs(2),
+        drain_budget: Duration::from_secs(60),
+    };
+
+    #[test]
+    #[ignore = "mounts FUSE: run with `cargo test -p pdfs-fuse --lib sim::run -- --ignored`"]
+    fn one_client_on_a_good_link() {
+        run_seeds(&ONE_CLIENT_LAN, 12);
+    }
+
+    #[test]
+    #[ignore = "mounts FUSE: run with `cargo test -p pdfs-fuse --lib sim::run -- --ignored`"]
+    fn one_client_deleting_files_as_they_upload() {
+        run_seeds(&ONE_CLIENT_DELETES, 3);
+    }
+
+    #[test]
+    #[ignore = "mounts FUSE: run with `cargo test -p pdfs-fuse --lib sim::run -- --ignored`"]
+    fn one_client_with_stale_hashes_and_reordered_echoes() {
+        run_seeds(&ONE_CLIENT_ECHOES, 6);
+    }
+
+    #[test]
+    #[ignore = "mounts FUSE: run with `cargo test -p pdfs-fuse --lib sim::run -- --ignored`"]
+    fn one_client_on_a_flaky_link() {
+        run_seeds(&ONE_CLIENT_FLAKY, 4);
+    }
+
+    #[test]
+    #[ignore = "mounts FUSE: run with `cargo test -p pdfs-fuse --lib sim::run -- --ignored`"]
+    fn one_client_on_a_slow_link() {
+        run_seeds(&ONE_CLIENT_WIFI, 4);
+    }
+
+    #[test]
+    #[ignore = "mounts FUSE: run with `cargo test -p pdfs-fuse --lib sim::run -- --ignored`"]
+    fn three_clients_one_writer_each() {
+        run_seeds(&THREE_CLIENTS, 3);
+    }
+
+    #[test]
+    fn conflict_copies_are_recognised_by_name() {
+        assert!(is_conflict_copy("c0/x/a (sync-conflict 1790000000).txt"));
+        assert!(is_conflict_copy("recovered-XrPUSW5W"));
+        assert!(!is_conflict_copy("c0/x/a.txt"));
+    }
+
+    #[test]
+    fn a_write_kept_because_its_file_is_gone_is_recognised() {
+        let kept = "queued write conflicts; keeping a conflict copy uid=simvol~L10 \
+                    name=\"f.txt\" reason=\"the file was trashed remotely\"";
+        assert!(is_own_delete_kept(kept));
+        assert!(is_own_delete_kept(
+            &kept.replace("was trashed", "no longer exists")
+        ));
+        assert!(!is_own_delete_kept(
+            &kept.replace("the file was trashed remotely", "revision changed")
+        ));
+    }
+}
@@ -0,0 +1,322 @@
+//! Turns a call through a mount that never returns into a failed seed.
+//!
+//! A deadlock in a daemon leaves the run's own thread blocked in the kernel,
+//! where no budget check is reached, and a CI job then waits for its timeout.
+//! The watchdog runs beside the run. When what it was armed for outlives its
+//! limit, it aborts the FUSE connections of the run's mounts, so the blocked
+//! call fails and the run reports the hang, and writes where every thread was
+//! to `stacks.txt`.
+//!
+//! The stacks are taken in the process: no tracer can stop a thread that
+//! waits on a FUSE request, so `gdb` and `eu-stack` wait as long as the hang.
+//! Each thread is sent [`stack_signal`] and captures its own backtrace in the
+//! handler. A thread in the kernel takes the signal only once it leaves, so
+//! the mounts are aborted after the others have answered, and its backtrace
+//! is the call it was blocked in. Its kernel wait channel is recorded first.
+
+use std::collections::BTreeMap;
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::thread::JoinHandle;
+use std::time::{Duration, Instant};
+
+use parking_lot::Mutex;
+
+use super::daemon::wait_until;
+
+/// How long the threads that are not blocked in the kernel have to answer,
+/// and the blocked ones once the mounts are aborted.
+const ANSWER: Duration = Duration::from_secs(5);
+
+pub(crate) struct Watchdog {
+    shared: Arc<Shared>,
+    thread: Option<JoinHandle<()>>,
+}
+
+struct Shared {
+    /// The run's directory: its mounts are below it, and the stacks go in it.
+    dir: PathBuf,
+    armed: Mutex<Option<Armed>>,
+    /// What hung, once something has.
+    fired: Mutex<Option<Hung>>,
+    stop: AtomicBool,
+}
+
+struct Armed {
+    what: String,
+    limit: Duration,
+    since: Instant,
+}
+
+/// What hung, and where every thread was then.
+#[derive(Clone, Debug, PartialEq)]
+pub(crate) struct Hung {
+    pub(crate) what: String,
+    pub(crate) stacks: String,
+}
+
+/// Disarms the watchdog when dropped.
+pub(crate) struct Watching(Arc<Shared>);
+
+impl Watchdog {
+    pub(crate) fn new(dir: &Path) -> Self {
+        let shared = Arc::new(Shared {
+            dir: dir.to_path_buf(),
+            armed: Mutex::new(None),
+            fired: Mutex::new(None),
+            stop: AtomicBool::new(false),
+        });
+        let thread = {
+            let shared = shared.clone();
+            std::thread::Builder::new()
+                .name("sim-watchdog".into())
+                .spawn(move || watch(&shared))
+                .expect("spawn the simulation watchdog")
+        };
+        Self {
+            shared,
+            thread: Some(thread),
+        }
+    }
+
+    /// Watch `what` until the guard is dropped, and abort the mounts if it is
+    /// still going after `limit`.
+    pub(crate) fn arm(&self, limit: Duration, what: impl Into<String>) -> Watching {
+        *self.shared.armed.lock() = Some(Armed {
+            what: what.into(),
+            limit,
+            since: Instant::now(),
+        });
+        Watching(self.shared.clone())
+    }
+
+    /// What hung, if something did. Call [`Watchdog::stop`] first, or the
+    /// stacks may still be on their way.
+    pub(crate) fn fired(&self) -> Option<Hung> {
+        self.shared.fired.lock().clone()
+    }
+
+    /// Stop watching, once the stacks of a hang that was caught are taken.
+    pub(crate) fn stop(&mut self) {
+        self.shared.stop.store(true, Ordering::Relaxed);
+        if let Some(thread) = self.thread.take() {
+            let _ = thread.join();
+        }
+    }
+}
+
+impl Drop for Watching {
+    fn drop(&mut self) {
+        *self.0.armed.lock() = None;
+    }
+}
+
+impl Drop for Watchdog {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}
+
+fn watch(shared: &Shared) {
+    while !shared.stop.load(Ordering::Relaxed) {
+        std::thread::sleep(Duration::from_millis(200));
+        let hung = shared
+            .armed
+            .lock()
+            .as_ref()
+            .filter(|armed| armed.since.elapsed() > armed.limit)
+            .map(|armed| format!("{} has not returned after {:?}", armed.what, armed.limit));
+        let Some(hung) = hung else { continue };
+        *shared.armed.lock() = None;
+        let path = shared.dir.join("stacks.txt");
+        // Before anything is let go: the run reports the hang, not whatever
+        // the aborted call answers.
+        *shared.fired.lock() = Some(Hung {
+            what: format!("{hung}; the stacks are in {}", path.display()),
+            stacks: String::new(),
+        });
+        let stacks = take_stacks(|| abort_mounts_below(&shared.dir));
+        let what = match std::fs::write(&path, &stacks) {
+            Ok(()) => format!("{hung}; the stacks are in {}", path.display()),
+            Err(error) => format!("{hung}; the stacks could not be kept: {error}"),
+        };
+        *shared.fired.lock() = Some(Hung { what, stacks });
+    }
+}
+
+/// One thread of this process as the kernel sees it.
+struct Task {
+    tid: i32,
+    name: String,
+    /// `D` while it waits in the kernel uninterruptibly.
+    state: String,
+    wchan: String,
+}
+
+/// Where every other thread of this process is, with `release` called once
+/// those not blocked in the kernel have answered.
+fn take_stacks(release: impl FnOnce()) -> String {
+    let own = gettid();
+    let tasks = tasks();
+    STACKS.lock().clear();
+    install_stack_handler();
+    for task in &tasks {
+        if task.tid != own {
+            // SAFETY: tgkill only sends a signal, whose handler is installed.
+            unsafe {
+                libc::syscall(
+                    libc::SYS_tgkill,
+                    std::process::id() as i32,
+                    task.tid,
+                    stack_signal(),
+                )
+            };
+        }
+    }
+    let answered = |blocked: bool| {
+        let stacks = STACKS.lock();
+        tasks
+            .iter()
+            .filter(|task| task.tid != own && (blocked || task.state != "D"))
+            .all(|task| stacks.contains_key(&task.tid))
+    };
+    wait_until(ANSWER, || answered(false));
+    release();
+    wait_until(ANSWER, || answered(true));
+    let stacks = std::mem::take(&mut *STACKS.lock());
+    let mut out = String::new();
+    for task in tasks.iter().filter(|task| task.tid != own) {
+        out.push_str(&format!(
+            "thread {} {:?}, state {}, waiting in {}\n",
+            task.tid, task.name, task.state, task.wchan
+        ));
+        match stacks.get(&task.tid) {
+            Some(stack) => out.push_str(&format!("{stack}\n")),
+            None => out.push_str("  (no answer)\n\n"),
+        }
+    }
+    out
+}
+
+fn tasks() -> Vec<Task> {
+    let Ok(entries) = std::fs::read_dir("/proc/self/task") else {
+        return Vec::new();
+    };
+    let read = |dir: &Path, file: &str| {
+        std::fs::read_to_string(dir.join(file))
+            .unwrap_or_default()
+            .trim()
+            .to_owned()
+    };
+    entries
+        .flatten()
+        .filter_map(|entry| {
+            let tid = entry.file_name().to_str()?.parse().ok()?;
+            let dir = entry.path();
+            // The state follows the name in parentheses, which may hold spaces.
+            let stat = read(&dir, "stat");
+            let state = stat.rsplit_once(") ")?.1.split(' ').next()?.to_owned();
+            Some(Task {
+                tid,
+                name: read(&dir, "comm"),
+                state,
+                wchan: read(&dir, "wchan"),
+            })
+        })
+        .collect()
+}
+
+/// The backtraces the threads captured, by thread id.
+static STACKS: Mutex<BTreeMap<i32, std::backtrace::Backtrace>> = Mutex::new(BTreeMap::new());
+
+/// The signal that asks a thread for its stack: one of the real-time signals
+/// that nothing in the daemon uses.
+fn stack_signal() -> i32 {
+    libc::SIGRTMIN() + 7
+}
+
+fn install_stack_handler() {
+    static INSTALLED: std::sync::Once = std::sync::Once::new();
+    extern "C" fn handler(_: i32) {
+        // Not async-signal-safe: the capture allocates. The process is being
+        // taken down for a hang anyway, and a thread interrupted inside the
+        // allocator only fails to answer.
+        let stack = std::backtrace::Backtrace::force_capture();
+        STACKS.lock().insert(gettid(), stack);
+    }
+    INSTALLED.call_once(|| {
+        // SAFETY: a zeroed sigaction with a handler and SA_RESTART is valid,
+        // and the handler only touches `STACKS`.
+        unsafe {
+            let mut action: libc::sigaction = std::mem::zeroed();
+            action.sa_sigaction = handler as extern "C" fn(i32) as usize;
+            action.sa_flags = libc::SA_RESTART;
+            libc::sigemptyset(&mut action.sa_mask);
+            libc::sigaction(stack_signal(), &action, std::ptr::null_mut());
+        }
+    });
+}
+
+fn gettid() -> i32 {
+    // SAFETY: gettid has no arguments and cannot fail.
+    unsafe { libc::gettid() }
+}
+
+/// Abort the FUSE connection of every mount below `dir`. Its connection is
+/// named by the mount's device minor, and the mount's owner may abort it.
+fn abort_mounts_below(dir: &Path) {
+    let Ok(mountinfo) = std::fs::read_to_string("/proc/self/mountinfo") else {
+        return;
+    };
+    for line in mountinfo.lines() {
+        let fields: Vec<&str> = line.split(' ').collect();
+        let (Some(device), Some(mountpoint)) = (fields.get(2), fields.get(4)) else {
+            continue;
+        };
+        if !Path::new(mountpoint).starts_with(dir) {
+            continue;
+        }
+        if let Some((_, minor)) = device.split_once(':') {
+            let _ = std::fs::write(format!("/sys/fs/fuse/connections/{minor}/abort"), "1");
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::sim::daemon::scratch;
+
+    #[test]
+    #[ignore = "signals every thread of the test process: run with `cargo test -p pdfs-fuse sim:: -- --ignored`"]
+    fn a_call_past_its_limit_is_reported_with_the_stacks() {
+        let dir = scratch("watchdog");
+        let mut watchdog = Watchdog::new(&dir);
+        {
+            let _watching = watchdog.arm(Duration::from_millis(100), "a nap");
+            std::thread::sleep(Duration::from_secs(1));
+        }
+        watchdog.stop();
+        let hung = watchdog.fired().expect("the watchdog fired");
+        assert!(
+            hung.what.starts_with("a nap has not returned after"),
+            "{hung:?}"
+        );
+        assert!(hung.stacks.contains("a_call_past_its_limit"), "{hung:?}");
+        let kept = std::fs::read_to_string(dir.join("stacks.txt")).unwrap_or_default();
+        assert_eq!(kept, hung.stacks);
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn a_call_within_its_limit_is_not() {
+        let dir = scratch("watchdog-quiet");
+        let watchdog = Watchdog::new(&dir);
+        drop(watchdog.arm(Duration::from_millis(100), "a quick call"));
+        std::thread::sleep(Duration::from_millis(500));
+        assert_eq!(watchdog.fired(), None);
+        drop(watchdog);
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+}
@@ -128,7 +128,62 @@ pub(crate) struct WriteHandle {
    pub(crate) open_count: usize,
 }

-/// A released write whose upload has not happened yet (offline.md Phase 3).
+impl WriteHandle {
+    /// A handle on a file `create` just made: an empty base, so everything
+    /// written through it is authored.
+    ///
+    /// The base is `node` as it actually exists — the empty file the server just
+    /// minted, or a queued create's placeholder — never the local clock or a
+    /// blank. `queue_revision` turns it into `StagedWrite::based_on` and the
+    /// drain compares the remote against that. A `now_secs()` mtime differs from
+    /// the server's stamp by the create round-trip. A missing revision id drops
+    /// the check to `(mtime, size)`, and moving or renaming the file advances
+    /// its mtime on the server. Either way the first write to a brand-new file
+    /// lands as a conflict copy of its own empty create (`docs/BUGS.md` B113).
+    pub(crate) fn created(ino: u64, node: &Node, file: File, path: PathBuf) -> Self {
+        Self {
+            ino,
+            uid: node.uid.clone(),
+            file: Arc::new(file),
+            path,
+            written: Intervals::default(),
+            len: 0,
+            base_size: 0,
+            base_mtime: node.modification_time,
+            base_revision_id: crate::node_revision_id(node),
+            dirty: false,
+            open_count: 0,
+        }
+    }
+
+    /// Write over `node` from now on: a revision this daemon has just put on the
+    /// server under the handle, by sealing an upload or by landing the queued
+    /// create the handle was opened on. The base the handle opened over is gone,
+    /// and keeping it would make the drain read our own revision as another
+    /// device's edit.
+    pub(crate) fn rebase_onto(&mut self, node: &Node) {
+        self.base_mtime = node.modification_time;
+        self.base_size = crate::node_size(node);
+        self.base_revision_id = crate::node_revision_id(node);
+    }
+
+    /// Account for `[offset, end)` having been written through this handle.
+    ///
+    /// A write past the end leaves a hole that reads as zeros, exactly like a
+    /// grow through `setattr`, so the hole is authored too. Left unauthored, a
+    /// hole below the base size was refilled from the base at commit: a file
+    /// shrunk and then written past its new end got its old bytes back.
+    pub(crate) fn record_write(&mut self, offset: u64, end: u64) {
+        if offset > self.len {
+            self.written.add(self.len, offset);
+        }
+        self.written.add(offset, end);
+        self.len = self.len.max(end);
+        self.dirty = true;
+    }
+}
+
+/// A released write whose upload has not happened yet.
 ///
 /// The bytes live in the content cache's staging dir and the intent lives in the
 /// `pending_op` table; this pairs them in memory so a read can be served without
@@ -146,8 +201,29 @@ pub(crate) struct PendingRevision {
 /// time so this module stays free of `fuser`.
 pub(crate) type DirListing = Vec<(u64, bool, String)>;

+/// Where [`State::next_ino`] starts: far above any local id a database hands
+/// out, so a fallback inode never names a node that has a row.
+pub(crate) const FALLBACK_INO: u64 = 1 << 48;
+
+/// The inode of the node with local id `lid` ([`Db::lids_for`]). One above the
+/// lid, so no node takes [`crate::ROOT_INO`], which each session uses for its
+/// own root. The same in every mount and after a restart.
+pub(crate) fn lid_ino(lid: i64) -> u64 {
+    lid.unsigned_abs() + crate::ROOT_INO
+}
+
+/// The local id of the node at inode `ino`, the inverse of [`lid_ino`]:
+/// `None` for the root and a fallback inode.
+pub(crate) fn ino_lid(ino: u64) -> Option<i64> {
+    (ino > crate::ROOT_INO && ino < FALLBACK_INO).then(|| (ino - crate::ROOT_INO) as i64)
+}
+
 /// Mutable inode bookkeeping, guarded by a mutex because fuser drives the
 /// `Filesystem` trait through `&self`.
+///
+/// One tree for every mount of the daemon. Each FUSE session sees it from its
+/// own root ([`State::roots`]) and calls that root inode 1; `ProtonFs`
+/// translates at the kernel boundary.
 pub(crate) struct State {
    /// inode -> node metadata.
    pub(crate) entries: HashMap<u64, Entry>,
@@ -156,6 +232,12 @@ pub(crate) struct State {
    /// Cached directory listings: parent inode -> child inodes. Presence of a
    /// key means the directory has been enumerated.
    pub(crate) children: HashMap<u64, Vec<u64>>,
+    /// The inodes some session has been rooted at ([`State::install_root`]).
+    /// A root is its own parent. Kept after its session unmounts: the node is
+    /// still one of ours.
+    pub(crate) roots: HashSet<u64>,
+    /// The next inode for a node the database could not give a local id, from
+    /// a range lids never reach ([`FALLBACK_INO`]).
    pub(crate) next_ino: u64,
    /// Shared write state keyed by inode. Concurrent writers share the scratch file.
    pub(crate) active_writes: HashMap<u64, WriteHandle>,
@@ -171,13 +253,13 @@ pub(crate) struct State {
    /// two pages shifted every later entry, and the caller silently skipped or
    /// repeated whatever crossed the page boundary. Each entry is
    /// `(ino, is_dir, name)` — the kernel type is mapped at reply time so this
-    /// module stays free of `fuser` (bugs.md B43).
+    /// module stays free of `fuser` (`docs/BUGS.md` B43).
    pub(crate) dir_snapshots: HashMap<u64, Arc<DirListing>>,
    /// Resident inode attributes whose effective access changed during an
    /// intern/root refresh. Core drains this set and notifies the matching
    /// kernel only after releasing the State lock.
    pub(crate) access_changes: HashSet<u64>,
-    /// Persisted shared-root authority, loaded once per inode space and updated
+    /// Persisted shared-root authority, loaded once and updated
    /// on every explicit role/tombstone change. Descendant inheritance reads
    /// this map instead of issuing one SQLite query per interned inode.
    pub(crate) share_access: HashMap<NodeUid, Access>,
@@ -245,15 +327,6 @@ pub(crate) struct StateGuard<'a> {
    db: &'a Arc<Db>,
 }

-/// Take a mount's inode lock through a [`StateGuard`], for the loops that walk
-/// every live mount rather than this `Core`'s own.
-pub(crate) fn lock_state<'a>(
-    state: &'a parking_lot::Mutex<State>,
-    db: &'a Arc<Db>,
-) -> StateGuard<'a> {
-    StateGuard::new(state.lock(), db)
-}
-
 impl<'a> StateGuard<'a> {
    pub(crate) fn new(guard: parking_lot::MutexGuard<'a, State>, db: &'a Arc<Db>) -> Self {
        Self {
@@ -294,9 +367,6 @@ impl Drop for StateGuard<'_> {
 impl State {
    /// A fresh, empty inode space over `db`.
    ///
-    /// `next_ino` differs by caller: a real mount hands out [`crate::ROOT_INO`]
-    /// to its root and starts allocating above it, while a bare state under test
-    /// has no root and starts at 1.
    /// Apply the write-throughs this state owes SQLite, here and now.
    ///
    /// Production code never calls this: [`StateGuard`] releases the inode lock
@@ -323,12 +393,15 @@ impl State {
        self.db.clone()
    }

-    pub(crate) fn new(db: Arc<Db>, share_access: HashMap<NodeUid, Access>, next_ino: u64) -> Self {
+    /// A fresh, empty tree over `db`. A node's inode comes from its local id
+    /// ([`lid_ino`]).
+    pub(crate) fn new(db: Arc<Db>, share_access: HashMap<NodeUid, Access>) -> Self {
        Self {
            entries: HashMap::new(),
            by_uid: HashMap::new(),
            children: HashMap::new(),
-            next_ino,
+            roots: HashSet::new(),
+            next_ino: FALLBACK_INO,
            active_writes: HashMap::new(),
            handles: HashMap::new(),
            next_fh: 1,
@@ -339,18 +412,55 @@ impl State {
            outbox: Vec::new(),
        }
    }
-    /// Whether `uid` names an owned node currently reachable from this mount's
-    /// root. Resident entries can outlive their dentries for open-handle and
-    /// access-revocation semantics, so `by_uid` membership alone is not proof
-    /// that a control-socket operation may address the node.
-    pub(crate) fn owns_visible_uid(&self, uid: &NodeUid) -> bool {
-        let Some(root) = self.entries.get(&crate::ROOT_INO) else {
-            return false;
-        };
-        if uid.volume_id != root.uid.volume_id {
-            return false;
+    /// Make `root` the root of a session and return its inode, which comes
+    /// from its local id like any other node's.
+    ///
+    /// The root is always owned. It must never be classified as a shared root,
+    /// even when the API returns membership data (which happens when the owner
+    /// shares the folder with someone else), so a stale share row a downgrade
+    /// may have left for it is dropped. A node already in the tree keeps its
+    /// inode and its lookups, and stops naming a parent: a session's `..` at
+    /// its root is the root.
+    pub(crate) fn install_root(&mut self, root: Node) -> u64 {
+        if let Err(e) = self.db.upsert_node(&root) {
+            warn!(uid = %root.uid, error = %e, "db upsert root failed");
        }
+        self.share_access.remove(&root.uid);
+        let _ = self.db.delete_share_access(&root.uid);
+        let ino = match self.by_uid.get(&root.uid) {
+            Some(&ino) => ino,
+            None => self.new_inos(&[&root])[&root.uid],
+        };
+        if let Some(old) = self.entries.get(&ino).map(|e| e.parent)
+            && old != ino
+            && let Some(kids) = self.children.get_mut(&old)
+        {
+            kids.retain(|&k| k != ino);
+        }
+        self.by_uid.insert(root.uid.clone(), ino);
+        let lookup_count = self.entries.get(&ino).map_or(1, |e| e.lookup_count.max(1));
+        self.entries.insert(
+            ino,
+            Entry {
+                uid: root.uid.clone(),
+                parent: ino,
+                node: root,
+                access: Access::Owner,
+                lookup_count,
+                open_count: 0,
+                unlinked: false,
+            },
+        );
+        self.roots.insert(ino);
+        ino
+    }

+    /// Whether `uid` names an owned node currently reachable from one of
+    /// `roots`, the roots of the sessions that are mounted. Resident entries
+    /// can outlive their dentries for open-handle and access-revocation
+    /// semantics, so `by_uid` membership alone is not proof that a
+    /// control-socket operation may address the node.
+    pub(crate) fn owns_visible_uid(&self, uid: &NodeUid, roots: &[u64]) -> bool {
        let Some(&target) = self.by_uid.get(uid) else {
            return false;
        };
@@ -363,7 +473,9 @@ impl State {
            let Some(entry) = self.entries.get(&current) else {
                return false;
            };
-            if entry.uid.volume_id != root.uid.volume_id
+            // The node's root scopes it to its own volume, excluding foreign
+            // shared-with-me residents from uid-addressed sharing.
+            if entry.uid.volume_id != uid.volume_id
                || entry.unlinked
                || entry.node.trashed
                || entry.uid != entry.node.uid
@@ -371,7 +483,7 @@ impl State {
            {
                return false;
            }
-            if current == crate::ROOT_INO {
+            if roots.contains(&current) {
                return true;
            }

@@ -413,15 +525,17 @@ impl State {
        self.access_changes.drain().collect()
    }

-    /// Whether `uid` lives on the volume this mount is rooted in.
+    /// Whether `uid` lives on a volume some mount is rooted in.
    ///
    /// Used to decide how a node with no resolvable parent is classified:
    /// our own volume fails open (it is owned content), a foreign volume
    /// fails closed (it can only be there because of a share).
    pub(crate) fn is_own_volume(&self, uid: &NodeUid) -> bool {
-        self.entries
-            .get(&crate::ROOT_INO)
-            .is_some_and(|root| root.uid.volume_id == uid.volume_id)
+        self.roots.iter().any(|ino| {
+            self.entries
+                .get(ino)
+                .is_some_and(|root| root.uid.volume_id == uid.volume_id)
+        })
    }

    fn stored_share_access(&self, uid: &NodeUid) -> Option<Access> {
@@ -770,11 +884,59 @@ impl State {
        }
    }

-    pub(crate) fn intern(&mut self, parent: u64, node: Node) -> u64 {
+    /// Write `node` through as it is, in order with the tree's other changes.
+    pub(crate) fn write_through(&mut self, node: Node) {
+        self.outbox.push(DbWrite::Upsert(vec![node]));
+    }
+
+    pub(crate) fn intern(&mut self, parent: u64, mut node: Node) -> u64 {
+        self.keep_revision_mtime(&mut node);
        self.outbox.push(DbWrite::Upsert(vec![node.clone()]));
        self.intern_mem(parent, node)
    }

+    /// Keep what is already known of a file whose content has not changed.
+    ///
+    /// Drive stamps a link's `ModifyTime` on a rename or a move as well, while
+    /// POSIX leaves a file's mtime alone there. The content cache is keyed by
+    /// it, too: taking the new stamp made the cached bytes unreachable, so the
+    /// next partial write could not fill its gaps (docs/BUGS.md B123). The
+    /// active revision id says whether the content is still the same, and so
+    /// whether the size and digest a listing left out are still the ones known.
+    fn keep_revision_mtime(&self, node: &mut Node) {
+        let Some(entry) = self
+            .by_uid
+            .get(&node.uid)
+            .and_then(|ino| self.entries.get(ino))
+        else {
+            return;
+        };
+        if let (
+            NodeKind::File {
+                active_revision_id: Some(now),
+                claimed_size,
+                content_sha1,
+                ..
+            },
+            NodeKind::File {
+                active_revision_id: Some(was),
+                claimed_size: size_was,
+                content_sha1: sha1_was,
+                ..
+            },
+        ) = (&mut node.kind, &entry.node.kind)
+            && now == was
+        {
+            node.modification_time = entry.node.modification_time;
+            if claimed_size.is_none() {
+                *claimed_size = *size_was;
+            }
+            if content_sha1.is_none() {
+                content_sha1.clone_from(sha1_was);
+            }
+        }
+    }
+
    /// Allocate (or reuse) a stable inode for a node, updating the hot-cache maps
    /// only. Every caller owes the DB a write-through — see the callers below;
    /// the split exists so a batch can pay for one transaction instead of `n`.
@@ -784,11 +946,24 @@ impl State {
    }

    fn intern_mem_with_access(&mut self, parent: u64, node: Node, access: Access) -> u64 {
+        self.intern_mem_at(parent, node, access, None)
+    }
+
+    /// [`State::intern_mem_with_access`], with the inode a new entry takes when
+    /// the caller already has it ([`State::new_inos`]).
+    fn intern_mem_at(
+        &mut self,
+        parent: u64,
+        mut node: Node,
+        access: Access,
+        ino: Option<u64>,
+    ) -> u64 {
        if let Some(&ino) = self.by_uid.get(&node.uid) {
            let changed = self
                .entries
                .get(&ino)
                .is_some_and(|entry| entry.access != access);
+            self.keep_open_write_size(ino, &mut node);
            if let Some(e) = self.entries.get_mut(&ino) {
                e.node = node;
                e.parent = parent;
@@ -801,8 +976,13 @@ impl State {
            }
            return ino;
        }
-        let ino = self.next_ino;
-        self.next_ino += 1;
+        let ino = match ino {
+            Some(ino) => ino,
+            None => self
+                .new_inos(&[&node])
+                .remove(&node.uid)
+                .unwrap_or_default(),
+        };
        self.by_uid.insert(node.uid.clone(), ino);
        self.entries.insert(
            ino,
@@ -819,6 +999,41 @@ impl State {
        ino
    }

+    /// The inodes for nodes that have no entry yet, from their local ids, in
+    /// one transaction. Should the database fail, they come from
+    /// [`State::next_ino`] instead, so the mount keeps working, with inodes
+    /// that last only this run. So do the inodes of virtual folders, which are
+    /// never stored.
+    fn new_inos(&mut self, nodes: &[&Node]) -> HashMap<NodeUid, u64> {
+        let (virtual_nodes, stored): (Vec<&Node>, Vec<&Node>) = nodes
+            .iter()
+            .partition(|node| crate::r#virtual::is_virtual_uid(&node.uid));
+        let mut inos = match self.db.lids_for(&stored) {
+            Ok(lids) => stored
+                .iter()
+                .zip(lids)
+                .map(|(node, lid)| (node.uid.clone(), lid_ino(lid)))
+                .collect(),
+            Err(error) => {
+                warn!(%error, "no local ids for new inodes; numbering them for this run");
+                self.run_inos(&stored)
+            }
+        };
+        inos.extend(self.run_inos(&virtual_nodes));
+        inos
+    }
+
+    fn run_inos(&mut self, nodes: &[&Node]) -> HashMap<NodeUid, u64> {
+        nodes
+            .iter()
+            .map(|node| {
+                let ino = self.next_ino;
+                self.next_ino += 1;
+                (node.uid.clone(), ino)
+            })
+            .collect()
+    }
+
    /// Decrement lookup count for an inode and prune if lookup_count == 0 && open_count == 0 && unlinked.
    pub(crate) fn forget_lookup(&mut self, ino: u64, nlookup: u64) -> Option<(u64, String)> {
        if let Some(entry) = self.entries.get_mut(&ino) {
@@ -833,6 +1048,23 @@ impl State {

    /// Allocate (or reuse) a stable inode for a node that came *from* the
    /// database, which is why nothing is written back.
+    /// Carry the size and mtime of a file open for writing over onto `node`,
+    /// which is about to replace its entry.
+    ///
+    /// The open handle is ahead of anything Drive can report until release
+    /// queues it. Taking the remote's size shrank a SQLite database to its empty
+    /// create while SQLite held it open, and the kernel then capped every read
+    /// at that size (docs/BUGS.md B109).
+    pub(crate) fn keep_open_write_size(&self, ino: u64, node: &mut Node) {
+        let (Some(aw), Some(entry)) = (self.active_writes.get(&ino), self.entries.get(&ino)) else {
+            return;
+        };
+        if let NodeKind::File { claimed_size, .. } = &mut node.kind {
+            *claimed_size = Some(aw.len as i64);
+            node.modification_time = entry.node.modification_time;
+        }
+    }
+
    pub(crate) fn intern_from_db(&mut self, parent: u64, node: Node) -> u64 {
        self.intern_mem(parent, node)
    }
@@ -842,11 +1074,27 @@ impl State {
    ///
    /// This is what keeps `ls` on a large folder quick: one commit for the
    /// listing, rather than one autocommit — and one fsync — per child.
-    pub(crate) fn intern_batch(&mut self, parent: u64, nodes: Vec<Node>) -> Vec<u64> {
+    pub(crate) fn intern_batch(&mut self, parent: u64, mut nodes: Vec<Node>) -> Vec<u64> {
+        for node in &mut nodes {
+            self.keep_revision_mtime(node);
+        }
        self.outbox.push(DbWrite::Upsert(nodes.clone()));
+        let fresh: Vec<&Node> = nodes
+            .iter()
+            .filter(|node| !self.by_uid.contains_key(&node.uid))
+            .collect();
+        let mut inos = if fresh.is_empty() {
+            HashMap::new()
+        } else {
+            self.new_inos(&fresh)
+        };
        nodes
            .into_iter()
-            .map(|node| self.intern_mem(parent, node))
+            .map(|node| {
+                let access = self.access_for_node(parent, &node);
+                let ino = inos.remove(&node.uid);
+                self.intern_mem_at(parent, node, access, ino)
+            })
            .collect()
    }

@@ -950,7 +1198,7 @@ impl State {
    /// re-enumerate, which is the cheaper way to stay honest about what the
    /// server did. A queued rename cannot: re-enumerating needs the network, and
    /// the server has not been told yet in any case — so this *is* the tree's
-    /// new truth until the op drains (offline.md Phase 3b).
+    /// new truth until the op drains.
    pub(crate) fn rename_in_place(
        &mut self,
        ino: u64,
@@ -1069,7 +1317,7 @@ impl State {
    /// created offline, nothing at all), so this row is the only record that the
    /// file is as long as the caller was told it is. Without it a restart serves
    /// the stale size and the file reads as truncated — or empty — while its
-    /// bytes sit safely in staging (offline.md Phase 3).
+    /// bytes sit safely in staging.
    /// Returns the node to persist rather than queueing it in the outbox, and is
    /// the one mutation here whose write-through the caller must do itself:
    /// failure has to be reported, not logged. Dropping the row silently means
@@ -1088,6 +1336,13 @@ mod tests {
    use proton_drive_rs::ShareMembership;
    use proton_drive_rs::proton_sdk::ids::{LinkId, ShareId, ShareMembershipId, VolumeId};

+    #[test]
+    fn an_inode_gives_back_the_lid_it_was_made_from() {
+        assert_eq!(ino_lid(lid_ino(7)), Some(7));
+        assert_eq!(ino_lid(crate::ROOT_INO), None);
+        assert_eq!(ino_lid(FALLBACK_INO + 3), None);
+    }
+
    fn uid(link: &str) -> NodeUid {
        NodeUid::new(VolumeId::from("vol"), LinkId::from(link))
    }
@@ -1164,7 +1419,7 @@ mod tests {
        let dir = TempDir::new();
        let db = Db::open(&dir.0.join("cache.db")).unwrap();
        let share_access = db.all_share_access().unwrap();
-        let st = State::new(Arc::new(db), share_access, 1);
+        let st = State::new(Arc::new(db), share_access);
        (st, dir)
    }

@@ -1182,6 +1437,36 @@ mod tests {
        (st, dir, src, dst)
    }

+    /// A node's inode comes from its row's local id, so it is the same in
+    /// every mount, after the hot cache drops it, and after a restart.
+    #[test]
+    fn a_node_keeps_its_inode_across_mounts_evictions_and_restarts() {
+        let (mut st, _dir) = state();
+        let inos = st.intern_batch(
+            0,
+            vec![
+                node("a", "root", "a.txt", false),
+                node("b", "root", "b.txt", false),
+            ],
+        );
+        st.flush_outbox();
+        let db = st.db.clone();
+        assert_ne!(inos[0], inos[1]);
+        assert!(!inos.contains(&crate::ROOT_INO));
+
+        let mut other = State::new(db.clone(), HashMap::new());
+        assert_eq!(other.intern(0, node("b", "root", "b.txt", false)), inos[1]);
+
+        st.forget_mem(&uid("a"));
+        assert_eq!(st.intern(0, node("a", "root", "a.txt", false)), inos[0]);
+
+        let mut restarted = State::new(db, HashMap::new());
+        assert_eq!(
+            restarted.intern_batch(0, vec![node("a", "root", "a.txt", false)]),
+            [inos[0]]
+        );
+    }
+
    /// Audit A5. Moving a file out of a folder leaves that folder's DB row
    /// claiming a complete listing, so once the hot cache drops it, remote
    /// changes under it stop being seen. `relocate` has to clear both sides.
@@ -1247,7 +1532,7 @@ mod tests {
        let root = uid("root").to_string();
        let state = parking_lot::Mutex::new(st);
        {
-            let mut guard = lock_state(&state, &db);
+            let mut guard = StateGuard::new(state.lock(), &db);
            guard.intern(0, node("root", "none", "My Files", true));
            assert!(
                db.node_by_uid(&root).unwrap().is_none(),
@@ -1490,6 +1775,7 @@ mod tests {
            })
            .collect();
        st.next_ino = crate::ROOT_INO + nodes.len() as u64;
+        st.roots.insert(crate::ROOT_INO);
        // Reverse order so entries are inserted before their parents, matching
        // the hydration path's non-topological materialization.
        for (i, node) in nodes.iter().enumerate().rev() {
@@ -1863,4 +2149,137 @@ mod tests {
        let shared = st.intern(owned_root, shared);
        assert_eq!(st.entries[&shared].access, Access::Viewer);
    }
+
+    fn at_revision(mut node: Node, revision: &str, mtime: i64) -> Node {
+        node.modification_time = mtime;
+        if let NodeKind::File {
+            active_revision_id, ..
+        } = &mut node.kind
+        {
+            *active_revision_id = Some(revision.into());
+        }
+        node
+    }
+
+    #[test]
+    fn a_renamed_file_keeps_its_mtime_until_its_content_changes() {
+        let (mut st, _dir) = state();
+        let root = st.intern(0, node("root", "none", "My Files", true));
+        let mut file = node("file", "root", "a.txt", false);
+        if let NodeKind::File {
+            claimed_size,
+            total_size_on_storage,
+            ..
+        } = &mut file.kind
+        {
+            *claimed_size = Some(7);
+            *total_size_on_storage = 519;
+        }
+        let ino = st.intern(root, at_revision(file.clone(), "r1", 100));
+        // Drive stamps the link on a rename; the content is still r1.
+        let mut renamed = at_revision(file.clone(), "r1", 160);
+        renamed.name = "b.txt".into();
+        st.intern_batch(root, vec![renamed]);
+        assert_eq!(st.entries[&ino].node.modification_time, 100);
+        assert_eq!(st.entries[&ino].node.name, "b.txt");
+        // A listing that leaves the size out still describes revision r1.
+        let mut bare = at_revision(file.clone(), "r1", 170);
+        assert_eq!(crate::node_size(&st.entries[&ino].node), 7);
+        if let NodeKind::File { claimed_size, .. } = &mut bare.kind {
+            *claimed_size = None;
+        }
+        st.intern(root, bare);
+        assert_eq!(st.entries[&ino].node.modification_time, 100);
+        assert_eq!(crate::node_size(&st.entries[&ino].node), 7);
+        st.intern(root, at_revision(file, "r2", 200));
+        assert_eq!(st.entries[&ino].node.modification_time, 200);
+    }
+
+    fn handle(len: u64, base_size: u64) -> WriteHandle {
+        let path = std::env::temp_dir().join(format!("pdfs-handle-test-{}", std::process::id()));
+        let file = File::create(&path).unwrap();
+        let _ = std::fs::remove_file(&path);
+        WriteHandle {
+            ino: 2,
+            uid: uid("file"),
+            file: Arc::new(file),
+            path,
+            written: Intervals::default(),
+            len,
+            base_size,
+            base_mtime: 0,
+            base_revision_id: None,
+            dirty: false,
+            open_count: 1,
+        }
+    }
+
+    /// A file created offline is written while its queued create lands. The
+    /// placeholder had no revision, so the handle takes the empty file the
+    /// create made as its base (docs/BUGS.md B113).
+    #[test]
+    fn a_handle_on_a_placeholder_is_based_on_the_create_that_landed() {
+        let mut h = handle(0, 0);
+        assert_eq!(h.base_revision_id, None);
+        let mut landed = node("real", "root", "f.mkv", false);
+        landed.modification_time = 160;
+        if let NodeKind::File {
+            active_revision_id, ..
+        } = &mut landed.kind
+        {
+            *active_revision_id = Some("empty".into());
+        }
+        h.rebase_onto(&landed);
+        assert_eq!(h.base_mtime, 160);
+        assert_eq!(h.base_size, 0);
+        assert_eq!(h.base_revision_id.as_deref(), Some("empty"));
+    }
+
+    #[test]
+    fn a_listing_does_not_shrink_a_file_open_for_writing() {
+        let (mut st, _dir) = state();
+        let ino = st.intern(0, node("file", "root", "workload.db", false));
+        let mut h = handle(16384, 0);
+        h.ino = ino;
+        st.active_writes.insert(ino, h);
+        st.set_size(ino, 16384);
+        st.touch_mtime(ino, 500);
+
+        // The remote still holds the empty file the create sealed.
+        st.intern(0, node("file", "root", "workload.db", false));
+        assert_eq!(crate::node_size(&st.entries[&ino].node), 16384);
+        assert_eq!(st.entries[&ino].node.modification_time, 500);
+
+        // Once the handle is gone the remote is authoritative again.
+        st.active_writes.remove(&ino);
+        st.intern(0, node("file", "root", "workload.db", false));
+        assert_eq!(crate::node_size(&st.entries[&ino].node), 0);
+    }
+
+    #[test]
+    fn a_write_past_the_end_authors_the_hole_it_leaves() {
+        // Opened over a 100-byte base, shrunk to 10, then written at 50: bytes
+        // 10..50 are zeros now, not the base's bytes 10..50.
+        let mut h = handle(100, 100);
+        h.written.clip(10);
+        h.len = 10;
+        h.record_write(50, 60);
+        assert_eq!(h.len, 60);
+        assert_eq!(
+            h.written.segments(0, 60),
+            vec![(0, 10, false), (10, 60, true)],
+            "only the head still comes from the base"
+        );
+    }
+
+    #[test]
+    fn a_write_inside_the_file_leaves_the_rest_to_the_base() {
+        let mut h = handle(100, 100);
+        h.record_write(40, 50);
+        assert_eq!(h.len, 100);
+        assert_eq!(
+            h.written.segments(0, 100),
+            vec![(0, 40, false), (40, 50, true), (50, 100, false)]
+        );
+    }
 }
@@ -68,7 +68,7 @@ impl Core {
    /// docs for the identical/divergent policy.
    pub(crate) fn run_conflict_sweep_loop(&self) {
        // Both waits are interruptible, so teardown does not have to sit out a
-        // five-minute interval to join this thread (bugs.md B44).
+        // five-minute interval to join this thread (`docs/BUGS.md` B44).
        if !self.shutdown.sleep(CONFLICT_SWEEP_WARMUP) {
            return;
        }
@@ -165,7 +165,7 @@ impl Core {
        }
        match self
            .rt
-            .block_on(self.client.trash_nodes(std::slice::from_ref(uid)))
+            .block_on(self.drive.trash_nodes(std::slice::from_ref(uid)))
            .and_then(batch::into_unit)
        {
            Ok(()) => {}
@@ -175,10 +175,9 @@ impl Core {
                return;
            }
        }
-        // Every mount, not just the primary: a conflict copy inside a sync
-        // folder lives in that fork's inode space, and leaving it hooked up
-        // there keeps a node we have just trashed remotely visible and
-        // readable there (`docs/BUGS.md` B74).
+        // Leaving a conflict copy hooked up in the tree keeps a node we have
+        // just trashed remotely visible and readable in whichever mount shows
+        // it (`docs/BUGS.md` B74).
        self.for_each_state(|st| {
            st.forget_or_unlink(uid);
        });
@@ -1,4 +1,4 @@
-//! Two-way folder sync engine (devices.md Phase 2).
+//! Two-way folder sync engine.
 //!
 //! Each `mirror`-mode synced folder is kept mirrored between a local directory
 //! and a folder under this machine's Proton Drive device. A local filesystem
@@ -73,6 +73,9 @@ enum Applied {
    Downloaded,
    /// A conflict copy was kept.
    Conflict,
+    /// The local file to upload was deleted after the scan planned it. There is
+    /// nothing left to send, and the next pass sees the deletion (B108).
+    Vanished,
 }

 impl Core {
@@ -99,6 +102,9 @@ impl Core {

    /// One reconcile pass over a mirror folder, updating its `state` column.
    fn reconcile_pass(&self, folder: &StoredSyncFolder) {
+        if self.shutdown.is_stopping() {
+            return;
+        }
        // Hold the folder's lock for the whole pass so a mode switch can't evict the
        // local tree (and mount FUSE over it) while we walk and upload it.
        let lock = self.sync_lock(folder.id);
@@ -145,8 +151,6 @@ impl Core {
            self.push_pass(folder.id, &local_root, &remote_root, &rules)
        } else {
            match self.do_reconcile(folder.id, &local_root, &remote_root, &rules) {
-                Ok(outcome) => Ok(outcome),
-                Err(PassAbort::Failed(e)) => Err(e),
                // The user asked for on-demand while this pass was running. Rather
                // than make them wait out a walk-and-download whose results are
                // about to be deleted, drop it here and do the only part that still
@@ -161,6 +165,7 @@ impl Core {
                    self.progress_begin(folder.id);
                    self.push_pass(folder.id, &local_root, &remote_root, &rules)
                }
+                result => result,
            }
        };
        self.progress_end(folder.id);
@@ -213,7 +218,15 @@ impl Core {
                    );
                }
            }
-            Err(e) => {
+            // A push pass is never interrupted, so only the stop gets here: the
+            // folder keeps the state it had, which the next start's pass updates.
+            Err(PassAbort::Stopped | PassAbort::Interrupted) => {
+                info!(id = folder.id, "sync: pass cut short by the stop");
+                let _ = self
+                    .db
+                    .sync_folder_set_state(folder.id, &current.state, current.last_sync);
+            }
+            Err(PassAbort::Failed(e)) => {
                warn!(id = folder.id, error = %e, "sync: reconcile failed");
                let _ = self
                    .db
@@ -291,7 +304,7 @@ impl Core {
        local_root: &Path,
        remote_root: &NodeUid,
        rules: &IgnoreRules,
-    ) -> Result<Outcome, String> {
+    ) -> Result<Outcome, PassAbort> {
        let baseline = self
            .db
            .sync_entries(folder_id)
@@ -367,7 +380,7 @@ impl Core {
            HashMap::new()
        } else {
            self.rt
-                .block_on(self.client.enumerate_nodes_light(&check))
+                .block_on(self.drive.enumerate_nodes_light(&check))
                .map_err(|e| format!("resolve changed nodes: {e}"))?
                .into_iter()
                .filter(|n| !n.trashed)
@@ -397,7 +410,7 @@ impl Core {
                    &mut remote_dirs,
                    std::mem::take(&mut batch),
                    &mut outcome,
-                );
+                )?;
                batch_depth = depth;
            }
            let item = &local[rel];
@@ -495,7 +508,7 @@ impl Core {
            &mut remote_dirs,
            std::mem::take(&mut batch),
            &mut outcome,
-        );
+        )?;

        // Paths the baseline knows that are no longer on disk: the user deleted them
        // locally, and the deletion has to reach Drive before the mount starts
@@ -522,7 +535,7 @@ impl Core {
            };
            if let Err(e) = self
                .rt
-                .block_on(self.client.trash_nodes(&[uid]))
+                .block_on(self.drive.trash_nodes(&[uid]))
                .and_then(batch::into_unit)
            {
                warn!(rel, error = %e, "sync: trash remote failed");
@@ -622,7 +635,7 @@ impl Core {
                    &mut remote_dirs,
                    std::mem::take(&mut batch),
                    &mut outcome,
-                );
+                )?;
                batch_depth = depth;
                // A depth boundary is the pass's natural checkpoint — everything
                // queued has been applied, so stopping here leaves nothing half done.
@@ -773,7 +786,7 @@ impl Core {
                    let remote = r.expect("remote deletion requires a remote file");
                    if let Err(e) = self
                        .rt
-                        .block_on(self.client.trash_nodes(std::slice::from_ref(&remote.uid)))
+                        .block_on(self.drive.trash_nodes(std::slice::from_ref(&remote.uid)))
                        .and_then(batch::into_unit)
                    {
                        warn!(rel, error = %e, "sync: trash remote failed");
@@ -810,7 +823,7 @@ impl Core {
            &mut remote_dirs,
            std::mem::take(&mut batch),
            &mut outcome,
-        );
+        )?;

        // Deferred folder deletions, deepest first.
        delete_local_dirs.sort_by_key(|p| std::cmp::Reverse(p.matches('/').count()));
@@ -836,7 +849,7 @@ impl Core {
        for (rel, uid) in delete_remote_dirs {
            if let Err(e) = self
                .rt
-                .block_on(self.client.trash_nodes(&[uid]))
+                .block_on(self.drive.trash_nodes(&[uid]))
                .and_then(batch::into_unit)
            {
                warn!(rel, error = %e, "sync: trash remote folder failed");
@@ -891,14 +904,14 @@ impl Core {
    ) -> Result<(), String> {
        let uids = self
            .rt
-            .block_on(self.client.enumerate_folder_children_node_uids(folder))
+            .block_on(self.drive.enumerate_folder_children_node_uids(folder))
            .map_err(|e| format!("enumerate {folder}: {e}"))?;
        if uids.is_empty() {
            return Ok(());
        }
        let nodes = self
            .rt
-            .block_on(self.client.enumerate_nodes_light(&uids))
+            .block_on(self.drive.enumerate_nodes_light(&uids))
            .map_err(|e| format!("resolve nodes: {e}"))?;
        for node in nodes {
            if node.trashed || !node.is_folder() {
@@ -938,19 +951,22 @@ impl Core {
        // is safe precisely because the walk has applied nothing — a *partial*
        // remote map, on the other hand, would be read as "the remote deleted
        // everything we haven't reached yet", so it must never reach the diff.
+        if self.shutdown.is_stopping() {
+            return Err(PassAbort::Stopped);
+        }
        if self.ondemand_queued(folder_id) {
            return Err(PassAbort::Interrupted);
        }
        let uids = self
            .rt
-            .block_on(self.client.enumerate_folder_children_node_uids(folder))
+            .block_on(self.drive.enumerate_folder_children_node_uids(folder))
            .map_err(|e| format!("enumerate {folder}: {e}"))?;
        if uids.is_empty() {
            return Ok(());
        }
        let nodes = self
            .rt
-            .block_on(self.client.enumerate_nodes_light(&uids))
+            .block_on(self.drive.enumerate_nodes_light(&uids))
            .map_err(|e| format!("resolve nodes: {e}"))?;

        // Files whose recorded mtime no longer matches: their size has to be
@@ -968,7 +984,7 @@ impl Core {
            HashMap::new()
        } else {
            self.rt
-                .block_on(self.client.enumerate_nodes(&stale))
+                .block_on(self.drive.enumerate_nodes(&stale))
                .map_err(|e| format!("resolve nodes: {e}"))?
                .iter()
                .map(|n| (n.uid.to_string(), remote_file_sig(n).1))
@@ -1048,6 +1064,9 @@ impl Core {
    /// `remote_dirs` (so deeper paths resolve their parent), and what each op did
    /// is tallied into `outcome`. Driven by `block_on` from the (non-runtime) sync
    /// engine thread, spawning the tasks onto the shared runtime.
+    ///
+    /// Fails with [`PassAbort::Stopped`] once the daemon is stopping, after the
+    /// ops already sending have finished.
    fn flush_batch(
        &self,
        folder_id: i64,
@@ -1055,9 +1074,9 @@ impl Core {
        remote_dirs: &mut HashMap<String, NodeUid>,
        batch: Vec<Pending>,
        outcome: &mut Outcome,
-    ) {
+    ) -> Result<(), PassAbort> {
        if batch.is_empty() {
-            return;
+            return Ok(());
        }
        self.progress_queued(folder_id, batch.len());
        let core = self.clone();
@@ -1071,14 +1090,22 @@ impl Core {
                let root = root.clone();
                set.spawn(async move {
                    let _permit = sem.acquire_owned().await.expect("semaphore not closed");
-                    core.apply_pending(folder_id, &root, op).await
+                    // An op still waiting for its turn when the stop comes is
+                    // not started; the ones already sending finish.
+                    if core.shutdown.is_stopping() {
+                        return None;
+                    }
+                    Some(core.apply_pending(folder_id, &root, op).await)
                });
            }
            let mut out = Vec::new();
            let mut join_errors = 0usize;
            while let Some(joined) = set.join_next().await {
                match joined {
-                    Ok(result) => out.push(result),
+                    Ok(Some(result)) => out.push(result),
+                    Ok(None) => {}
+                    // The runtime ends with the daemon and cancels what is left.
+                    Err(e) if e.is_cancelled() => {}
                    Err(e) => {
                        join_errors += 1;
                        warn!(error = %e, "sync: task panicked");
@@ -1103,6 +1130,13 @@ impl Core {
                }
            }
        }
+        // The pass goes no further: the next depth's paths may need a folder
+        // this batch did not get to make, and went on to fail one by one
+        // (`docs/BUGS.md` B169).
+        if self.shutdown.is_stopping() {
+            return Err(PassAbort::Stopped);
+        }
+        Ok(())
    }

    /// Apply one [`Pending`] op (async, so it can run concurrently in a batch),
@@ -1136,7 +1170,7 @@ impl Core {
        match op {
            Pending::CreateDir { rel, parent } => {
                let uid = self
-                    .client
+                    .drive
                    .create_folder(parent, base_name(rel), Some(now_secs()))
                    .await
                    .map_err(|e| format!("create remote folder {rel}: {e}"))?;
@@ -1147,13 +1181,10 @@ impl Core {
                Ok(Applied::Dir(rel.clone(), uid))
            }
            Pending::UploadNew { rel, parent } => {
-                self.upload_new(folder_id, local_root, rel, parent).await?;
-                Ok(Applied::Uploaded)
+                self.upload_new(folder_id, local_root, rel, parent).await
            }
            Pending::UploadRevision { rel, uid } => {
-                self.upload_revision(folder_id, local_root, rel, uid)
-                    .await?;
-                Ok(Applied::Uploaded)
+                self.upload_revision(folder_id, local_root, rel, uid).await
            }
            Pending::Download {
                rel,
@@ -1217,10 +1248,12 @@ impl Core {
        local_root: &Path,
        rel: &str,
        parent: &NodeUid,
-    ) -> Result<(), String> {
+    ) -> Result<Applied, String> {
        let path = local_root.join(rel_to_path(rel));
        let name = base_name(rel);
-        let file = std::fs::File::open(&path).map_err(|e| format!("open {rel}: {e}"))?;
+        let Some(file) = open_to_upload(&path, rel)? else {
+            return Ok(Applied::Vanished);
+        };
        let meta = file.metadata().map_err(|e| format!("stat {rel}: {e}"))?;
        let mtime = system_mtime(&meta);
        // Taken from the descriptor being streamed, so it names the content that
@@ -1238,7 +1271,7 @@ impl Core {
                .begin(name, "", TransferDirection::Upload, meta.len()),
        );
        let uid = self
-            .client
+            .drive
            // Mirror push: the local file is authoritative. If a prior attempt was
            // interrupted mid-upload it left an unsealed draft of this name; recover
            // it even across a daemon restart (which rotates our client uid), so the
@@ -1261,7 +1294,8 @@ impl Core {
        self.invalidate_children_of(parent);
        warn_if_torn(rel, &path, streamed);
        self.record_file_baseline(folder_id, rel, Some(streamed), &uid)
-            .await
+            .await?;
+        Ok(Applied::Uploaded)
    }

    /// Upload a changed local file as a new revision of an existing remote node.
@@ -1271,9 +1305,11 @@ impl Core {
        local_root: &Path,
        rel: &str,
        uid: &NodeUid,
-    ) -> Result<(), String> {
+    ) -> Result<Applied, String> {
        let path = local_root.join(rel_to_path(rel));
-        let file = std::fs::File::open(&path).map_err(|e| format!("open {rel}: {e}"))?;
+        let Some(file) = open_to_upload(&path, rel)? else {
+            return Ok(Applied::Vanished);
+        };
        let meta = file.metadata().map_err(|e| format!("stat {rel}: {e}"))?;
        let mtime = system_mtime(&meta);
        let streamed = LocalSig::from(&meta);
@@ -1289,13 +1325,14 @@ impl Core {
                meta.len(),
            ),
        );
-        self.client
+        self.drive
            .upload_new_revision_from(uid, reader, meta.len() as i64, thumbnails, Some(mtime))
            .await
            .map_err(|e| format!("upload revision {rel}: {e}"))?;
        warn_if_torn(rel, &path, streamed);
        self.record_file_baseline(folder_id, rel, Some(streamed), uid)
-            .await
+            .await?;
+        Ok(Applied::Uploaded)
    }

    /// Download a remote file to its local path (atomically via a temp file),
@@ -1305,7 +1342,7 @@ impl Core {
    /// rename below is the destructive step, and the download in between can run
    /// for minutes, so the destination is re-examined right before it: a local
    /// file that no longer matches the plan is set aside as a conflict copy
-    /// instead of being replaced (bugs.md B39).
+    /// instead of being replaced (`docs/BUGS.md` B39).
    #[allow(clippy::too_many_arguments)]
    async fn download_file(
        &self,
@@ -1328,7 +1365,21 @@ impl Core {
                .map(|d| d.as_nanos())
                .unwrap_or(0)
        ));
-        {
+        // A file an on-demand mount already read, say one just moved here from
+        // it, is in the content cache under the same revision key.
+        let seeded = size > 0 && self.cache.copy_cached_to(uid, mtime, size as u64, &tmp);
+        if seeded {
+            std::fs::File::open(&tmp)
+                .and_then(|f| f.sync_all())
+                .map_err(|e| {
+                    let _ = std::fs::remove_file(&tmp);
+                    format!("sync tmp {rel}: {e}")
+                })?;
+            debug!(
+                rel,
+                "sync: placed from the content cache instead of downloading"
+            );
+        } else {
            let out = std::fs::File::create(&tmp).map_err(|e| format!("create tmp {rel}: {e}"))?;
            // Count the bytes as they land, so the download reports progress like
            // an on-demand hydration does.
@@ -1339,7 +1390,7 @@ impl Core {
                size.max(0) as u64,
            );
            let mut out = CountingWriter::new(out, &guard);
-            self.client
+            self.drive
                .download_file_to(uid, &mut out)
                .await
                .map_err(|e| {
@@ -1390,7 +1441,7 @@ impl Core {
    /// the pre-upload identity is what makes the next pass see the path as
    /// locally changed and upload a whole, clean revision over it. Recording the
    /// post-upload stat instead declared the torn revision synchronized and left
-    /// it as the file's content on Drive (bugs.md B40).
+    /// it as the file's content on Drive (`docs/BUGS.md` B40).
    async fn record_file_baseline(
        &self,
        folder_id: i64,
@@ -1404,7 +1455,7 @@ impl Core {
        let (lmtime, lsize) = (local.mtime, local.size);
        // Re-fetch the node so the stored remote signature is exactly what a walk
        // will report next time.
-        let (rmtime, rsize) = match self.client.enumerate_nodes(std::slice::from_ref(uid)).await {
+        let (rmtime, rsize) = match self.drive.enumerate_nodes(std::slice::from_ref(uid)).await {
            Ok(nodes) => nodes
                .first()
                .map(remote_file_sig)
@@ -1431,13 +1482,30 @@ impl Core {
    }
 }

+/// Open a local file for upload, or `None` when it is gone.
+///
+/// A scan plans uploads from a listing, and the file can be deleted before its
+/// upload starts — a build or a test tree cleaned up mid-pass. That is not a
+/// failure: the next pass sees the deletion. Counting it as one put the folder
+/// in `error` for a file nobody wanted any more (B108).
+fn open_to_upload(path: &Path, rel: &str) -> Result<Option<std::fs::File>, String> {
+    match std::fs::File::open(path) {
+        Ok(file) => Ok(Some(file)),
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
+            debug!(rel, "sync: file deleted before its upload; skipping");
+            Ok(None)
+        }
+        Err(e) => Err(format!("open {rel}: {e}")),
+    }
+}
+
 /// Say so when a file changed under an upload that was streaming it.
 ///
 /// Purely diagnostic — the correction is already in place, because the baseline
 /// records the identity the upload *read* rather than the one on disk now, so
 /// the next pass classifies the path as locally changed and replaces the torn
 /// revision. Without the log there is nothing in the journal to explain the
-/// extra revision (bugs.md B40).
+/// extra revision (`docs/BUGS.md` B40).
 fn warn_if_torn(rel: &str, path: &Path, streamed: LocalSig) {
    let now = local_sig(path);
    if !now.is_some_and(|now| now.same_content(&streamed)) {
@@ -1469,7 +1537,7 @@ fn local_sig(path: &Path) -> Option<LocalSig> {
 /// transfer started, and a download of a large file can run for minutes. Without
 /// this, a local edit completed inside that window was replaced by the remote
 /// version with no copy of it kept anywhere — the one shape of loss a sync
-/// engine must not have (bugs.md B39). Keeping the copy makes it re-upload as a
+/// engine must not have (`docs/BUGS.md` B39). Keeping the copy makes it re-upload as a
 /// new file on the next pass, which is the same resolution a both-sides-changed
 /// conflict already gets.
 ///
@@ -1505,7 +1573,7 @@ fn keep_racing_local_edit(path: &Path, expected: Option<LocalSig>) -> std::io::R
 /// exists, so the same removal was re-attempted and re-reported as an error on
 /// every pass, forever. Every other error is still an error, and keeping the
 /// baseline is exactly right there: the surviving file must not be mistaken for
-/// a new local creation on the next pass and uploaded back (bugs.md B42).
+/// a new local creation on the next pass and uploaded back (`docs/BUGS.md` B42).
 fn removed_locally(result: std::io::Result<()>) -> std::io::Result<()> {
    match result {
        Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(()),
@@ -1602,6 +1670,76 @@ fn walk_local_tree(
    Ok(())
 }

+/// Why the mirror copy at `rel` holds something Proton Drive does not, or
+/// `None` when everything under it is on Drive exactly as it is on disk.
+///
+/// A move out of a mirror folder removes the local copy once Drive has moved
+/// the node, so anything only this disk has would be lost with it: a file not
+/// uploaded yet, one edited since, a deletion not carried up yet, or anything
+/// the engine never uploads. That is why ignored names count here, and why the
+/// walk is its own rather than [`walk_local_tree`], which skips symlinks.
+pub(crate) fn mirror_subtree_unsynced(
+    root: &Path,
+    rel: &str,
+    baseline: &HashMap<String, StoredSyncEntry>,
+) -> Option<String> {
+    let mut seen = HashSet::new();
+    if let Some(reason) = unsynced_local(root, rel, baseline, &mut seen) {
+        return Some(reason);
+    }
+    let prefix = format!("{rel}/");
+    baseline
+        .keys()
+        .filter(|r| *r == rel || r.starts_with(&prefix))
+        .find(|r| !seen.contains(r.as_str()))
+        .map(|r| format!("{r} was deleted here but not on Proton Drive yet"))
+}
+
+fn unsynced_local(
+    root: &Path,
+    rel: &str,
+    baseline: &HashMap<String, StoredSyncEntry>,
+    seen: &mut HashSet<String>,
+) -> Option<String> {
+    let path = root.join(rel_to_path(rel));
+    let meta = match std::fs::symlink_metadata(&path) {
+        Ok(meta) => meta,
+        Err(e) => return Some(format!("cannot read {rel}: {e}")),
+    };
+    let Some(base) = baseline.get(rel) else {
+        return Some(format!("{rel} is not on Proton Drive yet"));
+    };
+    seen.insert(rel.to_string());
+    if meta.is_file() {
+        return (!LocalSig::from(&meta).same_content(&LocalSig::from(base)))
+            .then(|| format!("{rel} has changes that are not on Proton Drive yet"));
+    }
+    if !meta.is_dir() {
+        return Some(format!("{rel} is not a regular file or folder"));
+    }
+    let entries = match std::fs::read_dir(&path) {
+        Ok(entries) => entries,
+        Err(e) => return Some(format!("cannot read {rel}: {e}")),
+    };
+    for entry in entries {
+        let name = match entry {
+            Ok(entry) => entry.file_name(),
+            Err(e) => return Some(format!("cannot read {rel}: {e}")),
+        };
+        let Some(name) = name.to_str() else {
+            return Some(format!("{rel} holds a name that is not valid UTF-8"));
+        };
+        // A download the engine left half done; it is the engine's to clean up.
+        if name.contains(".pdfs-tmp-") {
+            continue;
+        }
+        if let Some(reason) = unsynced_local(root, &format!("{rel}/{name}"), baseline, seen) {
+            return Some(reason);
+        }
+    }
+    None
+}
+
 /// Publish a conflict copy without overwriting an earlier conflict bearing the
 /// same timestamp. The original is removed only after the new copy is durable.
 fn preserve_conflict_copy(path: &Path, stamp: i64) -> std::io::Result<PathBuf> {
@@ -1692,7 +1830,7 @@ fn system_mtime(meta: &std::fs::Metadata) -> i64 {
 ///
 /// Whole seconds cannot distinguish an edit made in the same second as the last
 /// sync from no edit at all, and if the size did not change either, that file
-/// was never uploaded (bugs.md B25). `None` for a clock or filesystem that
+/// was never uploaded (`docs/BUGS.md` B25). `None` for a clock or filesystem that
 /// cannot answer, which falls the comparison back to seconds rather than
 /// asserting an mtime of zero.
 fn system_mtime_ns(meta: &std::fs::Metadata) -> Option<i64> {
@@ -1707,7 +1845,7 @@ mod tests {

    /// A removal of something already gone has produced the state the sync
    /// engine wanted, so its baseline is dropped rather than retried forever.
-    /// Anything else stays an error and keeps the baseline (bugs.md B42).
+    /// Anything else stays an error and keeps the baseline (`docs/BUGS.md` B42).
    #[test]
    fn an_already_absent_path_counts_as_removed() {
        let root = std::env::temp_dir().join(format!("pdfs-b42-{}", std::process::id()));
@@ -1724,7 +1862,7 @@ mod tests {
    }

    /// The download guard: a destination that still matches the plan is
-    /// replaced silently, one that has moved on since is kept (bugs.md B39).
+    /// replaced silently, one that has moved on since is kept (`docs/BUGS.md` B39).
    #[test]
    fn a_download_keeps_a_local_edit_it_did_not_plan_for() {
        let root = std::env::temp_dir().join(format!("pdfs-b39-{}", std::process::id()));
@@ -2039,7 +2177,7 @@ mod tests {
        std::fs::remove_dir_all(&root).unwrap();
    }

-    /// A restored folder (features.md 5.2) starts with an empty baseline against
+    /// A restored folder starts with an empty baseline against
    /// an empty local directory and a full remote. That must reconcile as
    /// "download everything" rather than tripping the wipe guard — otherwise
    /// every restore would wedge its folder on the first pass.
@@ -2155,6 +2293,27 @@ mod tests {
        assert_eq!(remote_sig(&e), None);
    }

+    #[test]
+    fn a_file_deleted_before_its_upload_is_skipped_not_failed() {
+        let root = std::env::temp_dir().join(format!("pdfs-b108-{}", std::process::id()));
+        std::fs::create_dir_all(&root).unwrap();
+        let gone = root.join("gone.txt");
+        assert!(open_to_upload(&gone, "gone.txt").unwrap().is_none());
+
+        std::fs::write(&gone, b"x").unwrap();
+        assert!(open_to_upload(&gone, "gone.txt").unwrap().is_some());
+
+        // Other open failures still count as errors.
+        let err = open_to_upload(&gone.join("child"), "gone.txt/child");
+        assert!(err.unwrap_err().starts_with("open gone.txt/child:"));
+        let _ = std::fs::remove_dir_all(&root);
+
+        let mut o = Outcome::default();
+        o.record(&Applied::Vanished);
+        assert!(o.is_empty());
+        assert_eq!(o.errors, 0);
+    }
+
    #[test]
    fn outcome_summarises_only_what_it_moved() {
        let mut o = Outcome::default();
@@ -2346,6 +2505,94 @@ mod tests {
        );
    }

+    /// A baseline row recording `path` as it is on disk right now.
+    fn synced_row(root: &Path, rel: &str) -> (String, StoredSyncEntry) {
+        let meta = std::fs::symlink_metadata(root.join(rel_to_path(rel))).unwrap();
+        let sig = LocalSig::from(&meta);
+        let entry = StoredSyncEntry {
+            rel_path: rel.to_string(),
+            remote_uid: Some(format!("vol~{rel}")),
+            local_mtime: sig.mtime,
+            local_mtime_ns: sig.mtime_ns,
+            local_size: sig.size,
+            remote_rev: None,
+            remote_hash: None,
+        };
+        (rel.to_string(), entry)
+    }
+
+    fn synced_subtree(name: &str) -> (PathBuf, HashMap<String, StoredSyncEntry>) {
+        let root = sync_test_dir(name);
+        std::fs::create_dir_all(root.join("dir/sub")).unwrap();
+        std::fs::write(root.join("dir/a.txt"), b"a").unwrap();
+        std::fs::write(root.join("dir/sub/b.txt"), b"b").unwrap();
+        let baseline = ["dir", "dir/sub", "dir/a.txt", "dir/sub/b.txt"]
+            .into_iter()
+            .map(|rel| synced_row(&root, rel))
+            .collect();
+        (root, baseline)
+    }
+
+    #[test]
+    fn a_fully_synced_mirror_subtree_may_leave() {
+        let (root, baseline) = synced_subtree("move-synced");
+        let reason = mirror_subtree_unsynced(&root, "dir", &baseline);
+        std::fs::remove_dir_all(&root).unwrap();
+        assert_eq!(reason, None);
+    }
+
+    #[test]
+    fn a_mirror_subtree_with_a_file_not_uploaded_may_not_leave() {
+        let (root, baseline) = synced_subtree("move-new-file");
+        std::fs::write(root.join("dir/sub/new.txt"), b"n").unwrap();
+        let reason = mirror_subtree_unsynced(&root, "dir", &baseline);
+        std::fs::remove_dir_all(&root).unwrap();
+        assert!(reason.unwrap().contains("dir/sub/new.txt"));
+    }
+
+    #[test]
+    fn a_mirror_subtree_with_an_edit_not_uploaded_may_not_leave() {
+        let (root, baseline) = synced_subtree("move-edit");
+        std::fs::write(root.join("dir/a.txt"), b"longer now").unwrap();
+        let reason = mirror_subtree_unsynced(&root, "dir", &baseline);
+        std::fs::remove_dir_all(&root).unwrap();
+        assert!(reason.unwrap().contains("dir/a.txt"));
+    }
+
+    #[test]
+    fn a_mirror_subtree_with_a_deletion_not_carried_up_may_not_leave() {
+        let (root, baseline) = synced_subtree("move-deleted");
+        std::fs::remove_file(root.join("dir/sub/b.txt")).unwrap();
+        let reason = mirror_subtree_unsynced(&root, "dir", &baseline);
+        std::fs::remove_dir_all(&root).unwrap();
+        assert!(reason.unwrap().contains("dir/sub/b.txt"));
+    }
+
+    #[test]
+    fn a_mirror_subtree_holding_a_symlink_may_not_leave() {
+        let (root, baseline) = synced_subtree("move-symlink");
+        std::os::unix::fs::symlink("a.txt", root.join("dir/link")).unwrap();
+        let reason = mirror_subtree_unsynced(&root, "dir", &baseline);
+        std::fs::remove_dir_all(&root).unwrap();
+        assert!(reason.unwrap().contains("dir/link"));
+    }
+
+    #[test]
+    fn a_name_prefixed_sibling_does_not_hold_a_mirror_subtree_back() {
+        let (root, mut baseline) = synced_subtree("move-sibling");
+        // Deleted here but not on Drive, yet outside the subtree being moved.
+        baseline.insert(
+            "dirt".to_string(),
+            StoredSyncEntry {
+                rel_path: "dirt".to_string(),
+                ..baseline["dir/a.txt"].clone()
+            },
+        );
+        let reason = mirror_subtree_unsynced(&root, "dir", &baseline);
+        std::fs::remove_dir_all(&root).unwrap();
+        assert_eq!(reason, None);
+    }
+
    /// The same rule one level up: if the sync root itself cannot be read, the
    /// pass sees nothing, and "nothing" must never mean "delete everything".
    #[test]
@@ -33,7 +33,7 @@ pub(crate) enum SyncMsg {
    /// Re-read the folder set and adjust the filesystem watches (after add/remove).
    Rewatch,
    /// The daemon is tearing down: finish the current pass and end the engine
-    /// thread, so the mount can join it (bugs.md B44).
+    /// thread, so the mount can join it (`docs/BUGS.md` B44).
    Stop,
 }

@@ -20,7 +20,7 @@ impl LocalSig {
    /// Nanoseconds decide it when both sides have them; otherwise the comparison
    /// falls back to whole seconds, which is what a baseline row written before
    /// schema 28 — or a filesystem that reports no sub-second time — can support
-    /// (bugs.md B25).
+    /// (`docs/BUGS.md` B25).
    pub(super) fn same_content(&self, other: &Self) -> bool {
        if self.size != other.size {
            return false;
@@ -108,6 +108,7 @@ impl Outcome {
            Applied::Uploaded => self.uploaded += 1,
            Applied::Downloaded => self.downloaded += 1,
            Applied::Conflict => self.conflicts += 1,
+            Applied::Vanished => {}
        }
    }

@@ -160,7 +161,7 @@ pub(super) enum Pending {
    /// was there. A download can run for minutes, so the apply step revalidates
    /// against it immediately before it renames over the destination: a writer
    /// that finished an edit in the meantime must not be overwritten without a
-    /// conflict copy (bugs.md B39).
+    /// conflict copy (`docs/BUGS.md` B39).
    Download {
        rel: String,
        uid: NodeUid,
@@ -226,6 +227,10 @@ pub(super) enum PassAbort {
    Interrupted,
    /// The pass could not establish its diff (a walk or the baseline load failed).
    Failed(String),
+    /// The daemon is stopping. What the pass sent before the stop has landed or
+    /// will be cancelled with the runtime; nothing more is sent, and the next
+    /// start's pass picks up from the baseline.
+    Stopped,
 }

 impl From<String> for PassAbort {
@@ -218,7 +218,7 @@ pub(super) fn plan_file(
    }

    let local_changed = local.is_some_and(|item| {
-        // Nanoseconds where both sides have them (bugs.md B25): whole seconds
+        // Nanoseconds where both sides have them (`docs/BUGS.md` B25): whole seconds
        // could not see an edit made in the same second as the last sync that
        // left the file the same length, so it was never uploaded.
        baseline.is_none_or(|base| !LocalSig::from(item).same_content(&LocalSig::from(base)))
@@ -291,7 +291,7 @@ mod file_plan_tests {

    /// Whole seconds cannot see an edit made inside the same second that leaves the
    /// file the same length, so a mirror silently stopped uploading it. With a
-    /// nanosecond time on both sides it is an ordinary local change (bugs.md B25).
+    /// nanosecond time on both sides it is an ordinary local change (`docs/BUGS.md` B25).
    #[test]
    fn a_same_second_same_size_edit_is_still_a_local_change() {
        let mut base = baseline(10, 20, 30, 40);
@@ -74,6 +74,26 @@ pub(crate) fn watchdog_ping() {
    let _ = notify("WATCHDOG=1\n");
 }

+/// Sleep for `duration`, pinging the watchdog on the way.
+///
+/// For the stretches where the daemon is alive but has no mount, and so no
+/// supervisor: waiting for a login, or backing off after a failed mount. The
+/// manager arms the watchdog when the process starts, so without these pings a
+/// daemon that is merely retrying is aborted after `WatchdogSec` and leaves a
+/// coredump instead of the error it was logging. Never use this while mounted:
+/// there the ping must prove the control socket answers.
+pub fn idle_sleep(duration: Duration) {
+    const CHUNK: Duration = Duration::from_secs(10);
+    let mut left = duration;
+    watchdog_ping();
+    while !left.is_zero() {
+        let step = left.min(CHUNK);
+        std::thread::sleep(step);
+        left -= step;
+        watchdog_ping();
+    }
+}
+
 /// Tell the manager the daemon is stopping, so a slow teardown is not mistaken
 /// for a hang by the watchdog it is racing.
 pub(crate) fn stopping() {
@@ -530,7 +530,7 @@ fn open_archive(

 /// The lowercase-hex SHA-1 of everything `reader` yields — the digest Proton's
 /// photo duplicate detection is keyed on.
-fn sha1_of(reader: &mut (dyn Read + Send)) -> CoreResult<String> {
+pub(crate) fn sha1_of(reader: &mut (dyn Read + Send)) -> CoreResult<String> {
    let mut hasher = Sha1::new();
    let mut buffer = vec![0u8; 256 * 1024];
    loop {
@@ -73,7 +73,7 @@ async fn run_uploads(
                .upload_thumbnails_async(t.path.clone(), t.name.clone())
                .await;
            match core
-                .client
+                .drive
                .upload_file_from(
                    &t.parent_uid,
                    &t.name,
@@ -238,14 +238,11 @@ impl Core {
            .map_err(|error| self.errno_error(error, "upload destination"))?;
        let new_uid = self
            .rt
-            .block_on(
-                self.client
-                    .create_folder(parent_uid, name, Some(now_secs())),
-            )
+            .block_on(self.drive.create_folder(parent_uid, name, Some(now_secs())))
            .map_err(|e| CoreError::from_api(&e, &format!("create folder {name}")))?;
        let node = self
-            .fetch_node(&new_uid)
-            .map_err(|e| self.errno_error(e, "fetch node"))?;
+            .fetch_minted_node(&new_uid, name)
+            .ok_or_else(|| minted_but_unlisted(name))?;
        let mut st = self.state();
        let ino = st.intern(pino, node);
        if let Some(kids) = st.children.get_mut(&pino)
@@ -46,6 +46,7 @@
 .badge-pinned { color: var(--success-color); }
 .badge-cached { color: var(--success-color); }
 .badge-cloud { color: color-mix(in srgb, currentColor 55%, transparent); }
+.badge-issue { color: var(--error-color); }
 .browser-statusbar { background-color: alpha(currentColor, 0.025); }
 scale.browser-status-meter trough { min-width: 104px; min-height: 6px; }
 .bulk-bar { padding: 6px 8px; border-radius: 12px; background: color-mix(in srgb, var(--accent-bg-color) 12%, transparent); }
@@ -75,8 +75,8 @@ use pdfs_core::control::{
    DirEntry, ErrorKind, ImportSummary, InvitationInfo, JobItem, MappingProgress, PendingOpInfo,
    PhotoItem, PhotoKind, PhotoMonth, PlaceInfo, PublicLinkInfo, RefreshScope, Request, Response,
    RestorableFolder, RestoreItem, RevisionInfo, SearchHit, ShareEntry, ShareEntryKind, SharedItem,
-    SyncFolderInfo, SyncPhase, SyncProgress, ThumbnailBuildStatus, Topic, TransferDirection,
-    TransferItem, send,
+    SyncFolderInfo, SyncIssue, SyncPhase, SyncProgress, ThumbnailBuildStatus, Topic,
+    TransferDirection, TransferItem, send,
 };

 use pdfs_core::mounts::{MountAccess, MountKind, MountMode, MountSpec};
@@ -119,6 +119,9 @@ struct Ui {
    /// keyring (a DBus round-trip). Populated at startup and updated only on
    /// login / logout. `None` = signed out.
    session: RefCell<Option<auth::StoredSession>>,
+    /// Whether this run already asked for the mailbox password of a locked
+    /// account, so a refresh never re-opens a dialog the user cancelled.
+    unlock_offered: Cell<bool>,
    /// Whether the last refresh saw a live mount daemon. Gates the unpin buttons
    /// (which need the daemon to evict + re-hydrate) and every mutating action.
    mounted: RefCell<bool>,
@@ -362,6 +365,7 @@ fn build_window(app: &adw::Application) {
        busy: Cell::new(0),
        opening: RefCell::new(HashSet::new()),
        session: RefCell::new(auth::load().ok()),
+        unlock_offered: Cell::new(false),
        mounted: RefCell::new(false),
        sidebar: sidebar_list.clone(),
        nav: split.clone(),
@@ -668,6 +672,15 @@ fn build_window(app: &adw::Application) {
        sync_sidebar(&ui_nav);
        match st.visible_child_name().as_deref() {
            Some("browser") => load_browser(&ui_nav),
+            // The Albums and Places listings are re-read in place. Loading the
+            // timeline instead would swap it in under the Albums or Places toggle.
+            Some("gallery") if !ui_nav.gallery.in_collection() => {
+                match ui_nav.gallery.view_switch.active() {
+                    VIEW_ALBUMS => load_albums(&ui_nav),
+                    VIEW_PLACES => load_places(&ui_nav),
+                    _ => load_gallery(&ui_nav, false),
+                }
+            }
            Some("gallery") => load_gallery(&ui_nav, false),
            // Every visit reads the page again. The rows already on screen stay
            // up while it does, so arriving costs no "Loading…" flash.
@@ -1199,7 +1212,7 @@ fn install_window_actions(ui: &Rc<Ui>, window: &adw::ApplicationWindow) {
            .application_icon("io.narl.proton-drive-linux")
            .version(pdfs_core::config::APP_VERSION)
            .developer_name("Nils Pukropp")
-            .website("https://github.com/narrrl/proton-drive-linux")
+            .website("https://proton-drive.narl.io")
            .issue_url("https://github.com/narrrl/proton-drive-linux/issues")
            .copyright("© 2026 Nils Pukropp (contact@narl.io)")
            .license_type(gtk4::License::MitX11)
@@ -341,6 +341,59 @@ fn detail_label(entry: &ActivityEntry) -> Option<String> {
            &[("name", alt)],
        ));
    }
+    if let Some((reason, copy)) = detail.split_once("; local changes uploaded as ") {
+        let args = [("name", copy)];
+        return Some(match edit_conflict(reason) {
+            // Translators: {name} is the copy the changes made on this
+            // computer were uploaded as.
+            EditConflict::Gone => gettext_f(
+                "It no longer exists on Proton Drive, so your changes were uploaded as {name}",
+                &args,
+            ),
+            // Translators: {name} is the copy the changes made on this
+            // computer were uploaded as.
+            EditConflict::Trashed => gettext_f(
+                "It was moved to the Trash on Proton Drive, so your changes were uploaded as {name}",
+                &args,
+            ),
+            // Translators: {name} is the copy the changes made on this
+            // computer were uploaded as.
+            EditConflict::Changed => gettext_f(
+                "It was changed on Proton Drive, so your changes were uploaded as {name}",
+                &args,
+            ),
+            // Translators: {name} is the copy the changes made on this
+            // computer were uploaded as.
+            EditConflict::Other => gettext_f("Your changes were uploaded as {name}", &args),
+        });
+    }
+    if let Some((reason, path)) = detail.split_once("; local changes kept at ") {
+        let path = tilde_path(path);
+        let args = [("path", path.as_str())];
+        return Some(match edit_conflict(reason) {
+            // Translators: {path} is the file on this computer that holds the
+            // changes which could not be uploaded.
+            EditConflict::Gone => gettext_f(
+                "It no longer exists on Proton Drive, so your changes were kept in {path}",
+                &args,
+            ),
+            // Translators: {path} is the file on this computer that holds the
+            // changes which could not be uploaded.
+            EditConflict::Trashed => gettext_f(
+                "It was moved to the Trash on Proton Drive, so your changes were kept in {path}",
+                &args,
+            ),
+            // Translators: {path} is the file on this computer that holds the
+            // changes which could not be uploaded.
+            EditConflict::Changed => gettext_f(
+                "It was changed on Proton Drive, so your changes were kept in {path}",
+                &args,
+            ),
+            // Translators: {path} is the file on this computer that holds the
+            // changes which could not be uploaded.
+            EditConflict::Other => gettext_f("Your changes were kept in {path}", &args),
+        });
+    }
    if let Some(base) = detail.strip_prefix("differs from ") {
        // Translators: {name} is the file the conflicting copy was made from.
        return Some(gettext_f("Differs from {name}", &[("name", base)]));
@@ -388,6 +441,26 @@ fn detail_label(entry: &ActivityEntry) -> Option<String> {
    Some(capitalize(detail))
 }

+/// Why a queued edit could not land on its file, from the reason the daemon
+/// gives before "; local changes uploaded as" or "; local changes kept at".
+enum EditConflict {
+    Gone,
+    Trashed,
+    Changed,
+    Other,
+}
+
+fn edit_conflict(reason: &str) -> EditConflict {
+    match reason {
+        "the file no longer exists remotely" => EditConflict::Gone,
+        "the file was trashed remotely" => EditConflict::Trashed,
+        r if r.starts_with("the remote revision changed under the queued write") => {
+            EditConflict::Changed
+        }
+        _ => EditConflict::Other,
+    }
+}
+
 /// A sync pass summary such as "2 uploaded, 1 folder(s) created", as a
 /// list of counts. `None` when a part is not one the daemon writes.
 fn sync_summary(detail: &str) -> Option<String> {
@@ -596,6 +669,38 @@ mod tests {
        assert_eq!(d.details, vec!["1 person can view"]);
    }

+    #[test]
+    fn an_edit_kept_as_a_copy_says_why_in_words() {
+        let d = describe(&entry(
+            ActivityKind::Upload,
+            "notes.txt",
+            "the remote revision changed under the queued write \
+             (based on revision r1, remote now at r2); \
+             local changes uploaded as notes (sync-conflict 1700000000).txt",
+            false,
+        ));
+        assert_eq!(
+            d.details,
+            vec![
+                "It was changed on Proton Drive, so your changes were uploaded as \
+                 notes (sync-conflict 1700000000).txt"
+            ]
+        );
+        let d = describe(&entry(
+            ActivityKind::Upload,
+            "notes.txt",
+            "the file was trashed remotely; local changes kept at /var/staging/7",
+            false,
+        ));
+        assert_eq!(
+            d.details,
+            vec![
+                "It was moved to the Trash on Proton Drive, so your changes were kept in \
+                 /var/staging/7"
+            ]
+        );
+    }
+
    #[test]
    fn unknown_details_show_as_written() {
        let d = describe(&entry(
@@ -832,8 +832,8 @@ fn show_location_column(ui: &Rc<Ui>, visible: bool) {
    }
 }

-/// The menu for one entry, in the order of `docs/UI_UX_PLAN.md` §6: open,
-/// offline, sharing, organising, and the destructive item last on its own.
+/// The menu for one entry, in a fixed order: open, offline, sharing,
+/// organising, and the destructive item last on its own.
 pub(crate) fn entry_context_menu(ui: &Rc<Ui>, entry: &DirEntry) -> ActionMenu {
    let mut menu = ActionMenu::new();
    let (ui_c, entry_c) = (ui.clone(), entry.clone());
@@ -1920,6 +1920,10 @@ pub(crate) fn prompt_rename(ui: &Rc<Ui>, entry: &DirEntry) {

 /// Pick a destination folder by browsing Drive's folders, and move `entries`
 /// there through the daemon.
+///
+/// Besides My files the picker offers every synced folder. A move into one is
+/// still made on Proton Drive, so nothing is downloaded or uploaded again; it
+/// is sent with absolute paths, which is how the daemon tells locations apart.
 pub(crate) fn prompt_move(ui: &Rc<Ui>, entries: Vec<DirEntry>) {
    if entries.is_empty() {
        return;
@@ -1967,6 +1971,7 @@ pub(crate) fn prompt_move(ui: &Rc<Ui>, entries: Vec<DirEntry>) {
    dialog.set_default_response(Some("move"));
    dialog.set_close_response("cancel");

+    let mountpoint = ui.dirs.resolved_mountpoint(&ui.dirs.load_config());
    let picker = Rc::new(MovePicker {
        ui: ui.clone(),
        dialog: dialog.clone(),
@@ -1974,28 +1979,93 @@ pub(crate) fn prompt_move(ui: &Rc<Ui>, entries: Vec<DirEntry>) {
        list,
        up: up.clone(),
        sources: sources.clone(),
-        folder: RefCell::new(String::new()),
+        folder: RefCell::new(MoveTarget::Locations),
        generation: Cell::new(0),
    });
    let picker_up = picker.clone();
    up.connect_clicked(move |_| {
-        let folder = picker_up.folder.borrow().clone();
-        let parent = folder.rfind('/').map(|i| &folder[..i]).unwrap_or_default();
-        picker_up.open(parent.to_string());
+        let parent = picker_up.folder.borrow().parent();
+        picker_up.open(parent);
    });
    // Start where the browser is: moving is most often one level up or down.
-    picker.open(ui.browser.path.borrow().clone());
+    picker.open(MoveTarget::Drive(ui.browser.path.borrow().clone()));

    let ui = ui.clone();
    let picker_done = picker.clone();
    dialog.connect_response(None, move |_, resp| {
-        if resp == "move" {
-            run_bulk_move(&ui, sources.clone(), picker_done.folder.borrow().clone());
+        if resp != "move" {
+            return;
+        }
+        match picker_done.folder.borrow().clone() {
+            MoveTarget::Locations => {}
+            MoveTarget::Drive(folder) => run_bulk_move(&ui, sources.clone(), folder),
+            MoveTarget::Synced { path, .. } => {
+                let absolute = sources
+                    .iter()
+                    .map(|rel| mountpoint.join(rel).to_string_lossy().into_owned())
+                    .collect();
+                run_bulk_move(&ui, absolute, path);
+            }
        }
    });
    dialog.present(ui_window(&picker.ui).as_ref());
 }

+/// Where the Move dialog is looking, and the destination if the user confirms.
+#[derive(Clone, Debug, PartialEq)]
+pub(crate) enum MoveTarget {
+    /// The list of places to move to: My files and each synced folder.
+    Locations,
+    /// A folder in My files, mountpoint-relative; empty for My files itself.
+    Drive(String),
+    /// A folder inside a synced folder, as an absolute local path. `root` is
+    /// the synced folder. A mirror folder is a plain directory, read from disk.
+    Synced {
+        root: String,
+        path: String,
+        mirror: bool,
+    },
+}
+
+impl MoveTarget {
+    /// One level up. The top of a location leads back to the list of them.
+    pub(crate) fn parent(&self) -> MoveTarget {
+        match self {
+            MoveTarget::Locations => MoveTarget::Locations,
+            MoveTarget::Drive(folder) if folder.is_empty() => MoveTarget::Locations,
+            MoveTarget::Drive(folder) => MoveTarget::Drive(
+                folder
+                    .rfind('/')
+                    .map(|i| folder[..i].to_string())
+                    .unwrap_or_default(),
+            ),
+            MoveTarget::Synced { root, path, .. } if path == root => MoveTarget::Locations,
+            MoveTarget::Synced { root, path, mirror } => MoveTarget::Synced {
+                root: root.clone(),
+                path: Path::new(path)
+                    .parent()
+                    .map(|p| p.to_string_lossy().into_owned())
+                    .unwrap_or_else(|| root.clone()),
+                mirror: *mirror,
+            },
+        }
+    }
+
+    /// `name` inside this folder, in the same form.
+    fn child(&self, name: &str) -> MoveTarget {
+        match self {
+            MoveTarget::Locations => MoveTarget::Locations,
+            MoveTarget::Drive(folder) if folder.is_empty() => MoveTarget::Drive(name.to_string()),
+            MoveTarget::Drive(folder) => MoveTarget::Drive(format!("{folder}/{name}")),
+            MoveTarget::Synced { root, path, mirror } => MoveTarget::Synced {
+                root: root.clone(),
+                path: Path::new(path).join(name).to_string_lossy().into_owned(),
+                mirror: *mirror,
+            },
+        }
+    }
+}
+
 /// The Move dialog's folder browser.
 struct MovePicker {
    ui: Rc<Ui>,
@@ -2006,71 +2076,81 @@ struct MovePicker {
    /// What is being moved, mountpoint-relative.
    sources: Vec<String>,
    /// The folder on show, and the destination if the user confirms now.
-    folder: RefCell<String>,
+    folder: RefCell<MoveTarget>,
    /// Drops a listing that arrives after the user went elsewhere.
    generation: Cell<u64>,
 }

 impl MovePicker {
-    fn open(self: &Rc<Self>, folder: String) {
+    fn open(self: &Rc<Self>, folder: MoveTarget) {
        let generation = self.generation.get().wrapping_add(1);
        self.generation.set(generation);
-        self.location.set_label(if folder.is_empty() {
-            "Proton Drive"
-        } else {
-            &folder
-        });
-        self.location.set_tooltip_text(Some(&folder));
-        self.up.set_sensitive(!folder.is_empty());
-        self.dialog
-            .set_response_enabled("move", move_target_allowed(&self.sources, &folder));
+        let (label, tooltip) = match &folder {
+            MoveTarget::Locations => (gettext("Locations"), String::new()),
+            MoveTarget::Drive(rel) if rel.is_empty() => (gettext("My files"), String::new()),
+            MoveTarget::Drive(rel) => (rel.clone(), rel.clone()),
+            MoveTarget::Synced { path, .. } => (path.clone(), path.clone()),
+        };
+        self.location.set_label(&label);
+        self.location.set_tooltip_text(Some(&tooltip));
+        self.up
+            .set_sensitive(!matches!(folder, MoveTarget::Locations));
+        let allowed = match &folder {
+            MoveTarget::Locations => false,
+            MoveTarget::Drive(rel) => move_target_allowed(&self.sources, rel),
+            // What is moved is in My files, so it cannot be in a synced folder.
+            MoveTarget::Synced { .. } => true,
+        };
+        self.dialog.set_response_enabled("move", allowed);
        *self.folder.borrow_mut() = folder.clone();
        while let Some(row) = self.list.first_child() {
            self.list.remove(&row);
        }
        self.list.append(&picker_note(&gettext("Loading…")));
-        let rx = spawn_request(
-            self.ui.dirs.control_socket(),
-            Request::ListDir {
-                path: folder.clone(),
-            },
-        );
+
        let picker = self.clone();
        glib::spawn_future_local(async move {
-            let result = rx.recv().await;
+            let listed = match &folder {
+                MoveTarget::Locations => picker.locations().await,
+                MoveTarget::Drive(rel) => picker.drive_folders(&folder, rel.clone()).await,
+                MoveTarget::Synced {
+                    path, mirror: true, ..
+                } => local_folders(&folder, path.clone()).await,
+                MoveTarget::Synced { path, .. } => {
+                    picker.drive_folders(&folder, path.clone()).await
+                }
+            };
            if picker.generation.get() != generation {
                return;
            }
            while let Some(row) = picker.list.first_child() {
                picker.list.remove(&row);
            }
-            let Ok(Ok(Response::Entries { entries })) = result else {
+            let Some(rows) = listed else {
                picker
                    .list
                    .append(&picker_note(&gettext("Couldn't read this folder.")));
                return;
            };
-            let mut folders: Vec<DirEntry> = entries.into_iter().filter(|e| e.is_dir).collect();
-            folders.sort_by_key(|e| e.name.to_lowercase());
            let mut shown = 0;
-            for entry in folders {
-                let path = if folder.is_empty() {
-                    entry.name.clone()
-                } else {
-                    format!("{folder}/{}", entry.name)
-                };
+            for (title, subtitle, target) in rows {
                // A folder cannot go inside itself, so do not offer to open it.
-                if picker.sources.contains(&path) {
+                if let MoveTarget::Drive(path) = &target
+                    && picker.sources.contains(path)
+                {
                    continue;
                }
                let row = adw::ActionRow::builder()
-                    .title(glib::markup_escape_text(&entry.name).as_str())
+                    .title(glib::markup_escape_text(&title).as_str())
                    .activatable(true)
                    .build();
+                if let Some(subtitle) = subtitle {
+                    row.set_subtitle(glib::markup_escape_text(&subtitle).as_str());
+                }
                row.add_prefix(&gtk4::Image::from_icon_name("folder-symbolic"));
                row.add_suffix(&gtk4::Image::from_icon_name("go-next-symbolic"));
                let open = picker.clone();
-                row.connect_activated(move |_| open.open(path.clone()));
+                row.connect_activated(move |_| open.open(target.clone()));
                picker.list.append(&row);
                shown += 1;
            }
@@ -2081,6 +2161,92 @@ impl MovePicker {
            }
        });
    }
+
+    /// My files and every synced folder, as rows of the top level.
+    async fn locations(&self) -> Option<Vec<PickerRow>> {
+        let mut rows = vec![(gettext("My files"), None, MoveTarget::Drive(String::new()))];
+        let rx = spawn_request(self.ui.dirs.control_socket(), Request::ListSyncFolders);
+        let Ok(Ok(Response::SyncFolders { mut items })) = rx.recv().await else {
+            // My files alone is still somewhere to move to.
+            return Some(rows);
+        };
+        items.sort_by_key(|f| f.local_path.to_lowercase());
+        for folder in items {
+            let name = Path::new(&folder.local_path)
+                .file_name()
+                .map(|n| n.to_string_lossy().into_owned())
+                .unwrap_or_else(|| folder.local_path.clone());
+            rows.push((
+                name,
+                Some(folder.local_path.clone()),
+                MoveTarget::Synced {
+                    root: folder.local_path.clone(),
+                    path: folder.local_path,
+                    mirror: folder.mode == "mirror",
+                },
+            ));
+        }
+        Some(rows)
+    }
+
+    /// The folders in a mounted folder: `folder` is mountpoint-relative for My
+    /// files and absolute for an on-demand synced folder.
+    async fn drive_folders(&self, here: &MoveTarget, folder: String) -> Option<Vec<PickerRow>> {
+        let rx = spawn_request(
+            self.ui.dirs.control_socket(),
+            Request::ListDir {
+                path: folder.clone(),
+            },
+        );
+        let Ok(Ok(Response::Entries { entries })) = rx.recv().await else {
+            return None;
+        };
+        let mut names: Vec<String> = entries
+            .into_iter()
+            .filter(|e| e.is_dir)
+            .map(|e| e.name)
+            .collect();
+        names.sort_by_key(|name| name.to_lowercase());
+        Some(
+            names
+                .into_iter()
+                .map(|name| {
+                    let target = here.child(&name);
+                    (name, None, target)
+                })
+                .collect(),
+        )
+    }
+}
+
+/// One row of the picker: its title, an optional subtitle, and where it leads.
+type PickerRow = (String, Option<String>, MoveTarget);
+
+/// The folders in a mirror folder's directory `path`, read from disk off the
+/// main thread. A mirror folder has no mount for `ListDir` to read.
+async fn local_folders(here: &MoveTarget, path: String) -> Option<Vec<PickerRow>> {
+    let names = gio::spawn_blocking(move || {
+        let mut names: Vec<String> = std::fs::read_dir(&path)
+            .ok()?
+            .flatten()
+            .filter(|e| e.file_type().is_ok_and(|t| t.is_dir()))
+            .filter_map(|e| e.file_name().into_string().ok())
+            .filter(|name| !name.contains(".pdfs-tmp-"))
+            .collect();
+        names.sort_by_key(|name| name.to_lowercase());
+        Some(names)
+    })
+    .await
+    .ok()??;
+    Some(
+        names
+            .into_iter()
+            .map(|name| {
+                let target = here.child(&name);
+                (name, None, target)
+            })
+            .collect(),
+    )
 }

 fn picker_note(text: &str) -> gtk4::ListBoxRow {
@@ -2329,9 +2495,13 @@ pub(crate) fn start_upload(ui: &Rc<Ui>, sources: Vec<String>) {
 }

 /// The sync-state badge for an entry: `(icon, css-class)`, or `None` for folders
-/// (which carry no per-file cache state). Pinned (kept offline) ranks above merely
+/// (which carry no per-file cache state). A sync issue ranks first, on folders
+/// too: the change waits for the user. Pinned (kept offline) ranks above merely
 /// cached (downloaded, evictable); everything else is online-only.
 pub(crate) fn badge_for(entry: &DirEntry) -> Option<(&'static str, &'static str)> {
+    if entry.issue.is_some() {
+        return Some(("dialog-warning-symbolic", "badge-issue"));
+    }
    if entry.is_dir {
        return None;
    }
@@ -2347,9 +2517,11 @@ pub(crate) fn badge_for(entry: &DirEntry) -> Option<(&'static str, &'static str)
 /// Paint `badge` to reflect the entry's sync state (see [`badge_for`]). Clears any
 /// prior colour class first, since list factories recycle cells.
 pub(crate) fn apply_badge(badge: &gtk4::Image, entry: &DirEntry) {
-    for class in ["badge-pinned", "badge-cached", "badge-cloud"] {
+    for class in ["badge-pinned", "badge-cached", "badge-cloud", "badge-issue"] {
        badge.remove_css_class(class);
    }
+    let issue = entry.issue.map(super::locations::issue_text);
+    badge.set_tooltip_text(issue.as_deref());
    match badge_for(entry) {
        Some((icon, class)) => {
            badge.set_icon_name(Some(icon));
@@ -2749,6 +2921,7 @@ pub(crate) fn repaint_search(ui: &Rc<Ui>, hits: &[SearchHit]) {
            shared_by_unverified: false,
            trashed_at: 0,
            trashed_from: None,
+            issue: None,
        })
        .collect();
    sort_entries(&mut entries, ui.browser.view.get());
@@ -2786,11 +2959,11 @@ fn listing_summary(files: usize, folders: usize, file_bytes: u64) -> String {
 #[cfg(test)]
 mod tests {
    use super::{
-        hit_location, listing_summary, move_target_allowed, show_thumbnail_build_progress,
-        sort_entries,
+        MoveTarget, badge_for, hit_location, listing_summary, move_target_allowed,
+        show_thumbnail_build_progress, sort_entries,
    };
    use pdfs_core::config::{FileSort, FilesView};
-    use pdfs_core::control::{DirEntry, ThumbnailBuildStatus};
+    use pdfs_core::control::{DirEntry, SyncIssue, ThumbnailBuildStatus};

    fn entry(name: &str, is_dir: bool, size: u64, modified: i64) -> DirEntry {
        DirEntry {
@@ -2808,6 +2981,7 @@ mod tests {
            shared_by_unverified: false,
            trashed_at: 0,
            trashed_from: None,
+            issue: None,
        }
    }

@@ -2815,6 +2989,20 @@ mod tests {
        entries.iter().map(|e| e.name.as_str()).collect()
    }

+    #[test]
+    fn a_sync_issue_shows_on_the_node_before_its_cache_state() {
+        let mut file = entry("a.txt", false, 1, 0);
+        file.pinned = true;
+        assert_eq!(badge_for(&file).unwrap().1, "badge-pinned");
+        file.issue = Some(SyncIssue::Quota);
+        assert_eq!(badge_for(&file).unwrap().1, "badge-issue");
+
+        let mut folder = entry("d", true, 0, 0);
+        assert_eq!(badge_for(&folder), None);
+        folder.issue = Some(SyncIssue::Missing);
+        assert_eq!(badge_for(&folder).unwrap().1, "badge-issue");
+    }
+
    #[test]
    fn a_search_hit_location_is_its_parent_folder() {
        assert_eq!(hit_location("Work/Old/a.txt"), "Work/Old");
@@ -2880,4 +3068,43 @@ mod tests {
        status.running = false;
        assert!(!show_thumbnail_build_progress(&status));
    }
+
+    #[test]
+    fn move_picker_climbs_from_a_location_top_to_the_list_of_locations() {
+        assert_eq!(
+            MoveTarget::Drive(String::new()).parent(),
+            MoveTarget::Locations
+        );
+        let root = MoveTarget::Synced {
+            root: "/home/u/Docs".into(),
+            path: "/home/u/Docs".into(),
+            mirror: true,
+        };
+        assert_eq!(root.parent(), MoveTarget::Locations);
+    }
+
+    #[test]
+    fn move_picker_climbs_one_folder_at_a_time_inside_a_location() {
+        assert_eq!(
+            MoveTarget::Drive("a/b".into()).parent(),
+            MoveTarget::Drive("a".into())
+        );
+        assert_eq!(
+            MoveTarget::Drive("a".into()).parent(),
+            MoveTarget::Drive(String::new())
+        );
+        let inner = MoveTarget::Synced {
+            root: "/home/u/Docs".into(),
+            path: "/home/u/Docs/x/y".into(),
+            mirror: false,
+        };
+        assert_eq!(
+            inner.parent(),
+            MoveTarget::Synced {
+                root: "/home/u/Docs".into(),
+                path: "/home/u/Docs/x".into(),
+                mirror: false,
+            }
+        );
+    }
 }
@@ -7,7 +7,7 @@
 //! `~/ProtonDrive` mount, plus each folder this computer backs up, whether it is
 //! a mirrored local directory or an on-demand FUSE session. The page is called
 //! *Locations* rather than *Mounts* because a mirror folder is a plain directory
-//! with no FUSE session behind it (mount-architecture.md §4).
+//! with no FUSE session behind it.
 //!
 //! The device rows drive the same control requests the Computers page used to:
 //! mode switch, sync now, remove. What is new here is that the primary mount is
@@ -70,8 +70,9 @@ pub(crate) struct LocationRow {
    progress: gtk4::ProgressBar,
 }

-/// What a queue row shows that can change: id, attempts, next attempt, parked.
-pub(crate) type QueueKey = (i64, i64, Option<i64>, bool);
+/// What a queue row shows that can change: id, attempts, next attempt, parked,
+/// issue.
+pub(crate) type QueueKey = (i64, i64, Option<i64>, bool, Option<SyncIssue>);

 /// The "Waiting to Upload" list: the daemon's pending-op queue.
 pub(crate) struct QueueState {
@@ -262,20 +263,22 @@ pub(crate) fn build_locations_page(history: &gtk4::Widget) -> (gtk4::Widget, Loc
    (frame.upcast(), widgets)
 }

-/// `child` in a clamp that scrolls vertically only, with page margins.
+/// `child` across the page's full width, scrolling vertically only, with page
+/// margins.
 fn scrolled_column(child: &impl IsA<gtk4::Widget>) -> gtk4::ScrolledWindow {
-    let clamp = adw::Clamp::builder().child(child).build();
-    clamp.set_margin_top(18);
-    clamp.set_margin_bottom(18);
-    clamp.set_margin_start(18);
-    clamp.set_margin_end(18);
+    let column = gtk4::Box::new(gtk4::Orientation::Vertical, 0);
+    column.append(child);
+    column.set_margin_top(18);
+    column.set_margin_bottom(18);
+    column.set_margin_start(18);
+    column.set_margin_end(18);
    // Never scroll sideways: a location's subtitle holds a full path, and letting
    // the row grow to fit one pushes the controls at its end off screen.
    // Constrained, the path ellipsizes and the controls stay reachable.
    gtk4::ScrolledWindow::builder()
        .vexpand(true)
        .hscrollbar_policy(gtk4::PolicyType::Never)
-        .child(&clamp)
+        .child(&column)
        .build()
 }

@@ -589,7 +592,7 @@ fn repaint_queue(ui: &Rc<Ui>, items: &[PendingOpInfo]) {
    items.sort_by_key(|op| (!op.failing, op.attempts == 0, op.id));
    let key: Vec<QueueKey> = items
        .iter()
-        .map(|op| (op.id, op.attempts, op.next_attempt_at, op.parked))
+        .map(|op| (op.id, op.attempts, op.next_attempt_at, op.parked, op.issue))
        .collect();
    if *queue.painted.borrow() == key {
        return;
@@ -646,6 +649,10 @@ fn queue_row(ui: &Rc<Ui>, op: &PendingOpInfo, now: i64) -> adw::ActionRow {
        "{action} · {state}",
        &[("action", &action), ("state", &state)],
    );
+    if let Some(issue) = op.issue {
+        subtitle.push('\n');
+        subtitle.push_str(&issue_text(issue));
+    }
    if let Some(error) = &op.last_error {
        subtitle.push('\n');
        // Translators: {n} is how many attempts failed, {error} the last error message.
@@ -660,7 +667,7 @@ fn queue_row(ui: &Rc<Ui>, op: &PendingOpInfo, now: i64) -> adw::ActionRow {
        .title(glib::markup_escape_text(&op.path).as_str())
        .subtitle(glib::markup_escape_text(&subtitle).as_str())
        .title_lines(1)
-        .subtitle_lines(3)
+        .subtitle_lines(if op.issue.is_some() { 5 } else { 3 })
        .tooltip_text(&op.path)
        .build();
    let image = gtk4::Image::from_icon_name(if op.failing {
@@ -685,9 +692,157 @@ fn queue_row(ui: &Rc<Ui>, op: &PendingOpInfo, now: i64) -> adw::ActionRow {
        retry.connect_clicked(move |_| retry_queued(&ui, Some(id)));
        row.add_suffix(&retry);
    }
+    if op.failing && op.exportable {
+        let export = gtk4::Button::builder()
+            .label(gettext("Export"))
+            .tooltip_text(gettext("Save a copy of this file's content elsewhere"))
+            .valign(gtk4::Align::Center)
+            .build();
+        export.add_css_class("flat");
+        let ui = ui.clone();
+        let id = op.id;
+        let name = Path::new(&op.path)
+            .file_name()
+            .map(|name| name.to_string_lossy().into_owned())
+            .unwrap_or_default();
+        export.connect_clicked(move |_| prompt_export_queued(&ui, id, &name));
+        row.add_suffix(&export);
+    }
+    if op.failing {
+        let discard = gtk4::Button::builder()
+            .label(gettext("Discard"))
+            .tooltip_text(gettext("Undo this change here instead of sending it"))
+            .valign(gtk4::Align::Center)
+            .build();
+        discard.add_css_class("flat");
+        let ui = ui.clone();
+        let id = op.id;
+        let path = op.path.clone();
+        let exportable = op.exportable;
+        discard.connect_clicked(move |_| prompt_discard_queued(&ui, id, &path, exportable));
+        row.add_suffix(&discard);
+    }
    row
 }

+/// What a sync issue means and what the user can do about it. The change stays
+/// queued either way.
+pub(crate) fn issue_text(issue: SyncIssue) -> String {
+    match issue {
+        SyncIssue::Quota => gettext(
+            "Your Proton Drive storage is full. Free up space or upgrade your plan, and this change uploads on its own.",
+        ),
+        SyncIssue::Access => gettext(
+            "You can no longer change this on Proton Drive. Ask the owner for edit access, or export the file to keep your version.",
+        ),
+        SyncIssue::Missing => gettext(
+            "The folder this change belongs in is gone from Proton Drive. Export the file to keep your version.",
+        ),
+        SyncIssue::Limit => gettext(
+            "Proton Drive's limit on items in a folder or on folder depth is reached. Make room in the folder, then retry.",
+        ),
+        SyncIssue::Rejected | SyncIssue::Unknown => {
+            gettext("Proton Drive refused this change. It stays queued and is tried again.")
+        }
+    }
+}
+
+/// Ask where to save a copy of a queued file's content, then have the daemon
+/// write it there. The change itself stays queued.
+fn prompt_export_queued(ui: &Rc<Ui>, id: i64, name: &str) {
+    let window = ui_window(ui);
+    let dialog = gtk4::FileDialog::builder()
+        .title(gettext("Export File"))
+        .initial_name(name)
+        .build();
+    let ui = ui.clone();
+    dialog.save(window.as_ref(), gio::Cancellable::NONE, move |res| {
+        let Ok(file) = res else { return };
+        let Some(dest) = file.path().and_then(|p| p.to_str().map(str::to_string)) else {
+            toast_error(
+                &ui,
+                &gettext("Couldn't export the file"),
+                &gettext("That location isn't a local file."),
+            );
+            return;
+        };
+        let rx = spawn_request(
+            ui.dirs.control_socket(),
+            Request::ExportPendingOp { id, dest },
+        );
+        let ui = ui.clone();
+        glib::spawn_future_local(async move {
+            match rx.recv().await {
+                Ok(Ok(Response::Ok { .. })) => toast(&ui, &gettext("File exported")),
+                Ok(Ok(Response::Error { message, kind })) => {
+                    toast_failure(&ui, &gettext("Couldn't export the file"), &message, kind)
+                }
+                _ => toast_error(
+                    &ui,
+                    &gettext("Couldn't export the file"),
+                    &gettext("The Proton Drive service didn't respond."),
+                ),
+            }
+        });
+    });
+}
+
+/// Confirm, then have the daemon drop a queued change and undo it here.
+fn prompt_discard_queued(ui: &Rc<Ui>, id: i64, path: &str, exportable: bool) {
+    let body = if exportable {
+        // Translators: {path} is the file whose queued change would be dropped.
+        gettext_f(
+            "Your changes to {path} are undone here and never reach Proton Drive. Export the file first to keep your version.",
+            &[("path", path)],
+        )
+    } else {
+        // Translators: {path} is the file or folder whose queued change would be dropped.
+        gettext_f(
+            "The change to {path} is undone here and never reaches Proton Drive.",
+            &[("path", path)],
+        )
+    };
+    let dialog = adw::AlertDialog::builder()
+        .heading(gettext("Discard Change?"))
+        .body(body)
+        .build();
+    dialog.add_response("cancel", &gettext("Cancel"));
+    dialog.add_response("discard", &gettext("Discard"));
+    dialog.set_response_appearance("discard", adw::ResponseAppearance::Destructive);
+    dialog.set_default_response(Some("cancel"));
+    dialog.set_close_response("cancel");
+    let window = ui_window(ui);
+    let ui = ui.clone();
+    dialog.connect_response(None, move |_, resp| {
+        if resp == "discard" {
+            discard_queued(&ui, id);
+        }
+    });
+    dialog.present(window.as_ref());
+}
+
+fn discard_queued(ui: &Rc<Ui>, id: i64) {
+    let rx = spawn_request(ui.dirs.control_socket(), Request::DiscardPendingOp { id });
+    let ui = ui.clone();
+    glib::spawn_future_local(async move {
+        match rx.recv().await {
+            Ok(Ok(Response::Ok { .. })) => {
+                toast(&ui, &gettext("Change discarded"));
+                ui.locations.queue.painted.borrow_mut().clear();
+                refresh_queue(&ui);
+            }
+            Ok(Ok(Response::Error { message, kind })) => {
+                toast_failure(&ui, &gettext("Couldn't discard the change"), &message, kind)
+            }
+            _ => toast_error(
+                &ui,
+                &gettext("Couldn't discard the change"),
+                &gettext("The Proton Drive service didn't respond."),
+            ),
+        }
+    });
+}
+
 /// Ask the daemon to stop waiting out one op's backoff, or every failed op's.
 fn retry_queued(ui: &Rc<Ui>, id: Option<i64>) {
    let rx = spawn_request(ui.dirs.control_socket(), Request::RetryPendingOp { id });
@@ -128,7 +128,12 @@ pub(crate) fn wire_login(ui: &Rc<Ui>) {

        set_signing_in(&ui, true);
        ui.login.login_status.set_text(&gettext("Signing in…"));
-        let (rx, totp_req_rx, hv_req_rx) = spawn_login(username, password);
+        let LoginChannels {
+            result: rx,
+            totp: totp_req_rx,
+            hv: hv_req_rx,
+            mailbox: mailbox_req_rx,
+        } = spawn_login(username, password);

        // Surface the 2FA dialog only if the SDK actually asks for a code (i.e.
        // the account has 2FA enabled). The worker blocks until the dialog feeds
@@ -157,6 +162,21 @@ pub(crate) fn wire_login(ui: &Rc<Ui>) {
            }
        });

+        // And for the mailbox password, which only a two-password account has.
+        // The worker asks again after a wrong answer, so this loops too.
+        let ui_mailbox = ui.clone();
+        glib::spawn_future_local(async move {
+            while let Ok((attempt, answer_tx)) = mailbox_req_rx.recv().await {
+                ask_mailbox(&ui_mailbox, attempt > 0, move |answer| {
+                    // A cancelled dialog drops the sender, which the worker
+                    // reads as a cancelled login.
+                    if let Some(answer) = answer {
+                        let _ = answer_tx.send(answer);
+                    }
+                });
+            }
+        });
+
        let ui = ui.clone();
        glib::spawn_future_local(async move {
            let result = rx
@@ -209,6 +229,12 @@ pub(crate) fn login_error_message(error: &pdfs_core::Error) -> String {
        pdfs_core::Error::Other(message) if message.contains("two-factor") => {
            gettext("Sign-in cancelled: no two-factor code was entered.")
        }
+        pdfs_core::Error::Other(message) if message.contains("mailbox") => {
+            gettext("Sign-in cancelled: no mailbox password was entered.")
+        }
+        pdfs_core::Error::WrongMailboxPassword => {
+            gettext("That mailbox password didn't unlock your account.")
+        }
        pdfs_core::Error::Other(message) if message.contains("verification") => gettext(
            "Sign-in cancelled: the verification wasn't completed. Sign in again to get a new one.",
        ),
@@ -220,26 +246,31 @@ pub(crate) fn login_error_message(error: &pdfs_core::Error) -> String {
    }
 }

+/// What the login worker asks the UI for, and how it reports back.
+pub(crate) struct LoginChannels {
+    /// The final outcome, once.
+    pub(crate) result: async_channel::Receiver<Result<(), String>>,
+    /// Fires only if the account needs a 2FA code; carries the sender for it.
+    pub(crate) totp: async_channel::Receiver<std::sync::mpsc::Sender<String>>,
+    /// Fires only if the sign-in is gated: the page to show, and the sender for
+    /// the token the user earns on it.
+    pub(crate) hv: async_channel::Receiver<(String, std::sync::mpsc::Sender<String>)>,
+    /// Fires only for a two-password account: how many answers were already
+    /// wrong, and the sender for the password and the "remember" choice.
+    pub(crate) mailbox: async_channel::Receiver<(u32, std::sync::mpsc::Sender<(String, bool)>)>,
+}
+
 /// Run the async SRP + optional 2FA login on a dedicated current-thread Tokio
-/// runtime. Returns two channels: the first yields the final login result once;
-/// the second fires *only if* the account needs a 2FA code, carrying a
-/// [`std::sync::mpsc::Sender`] the UI uses to feed the code back. The login
-/// closure blocks the worker on that sender until the dialog answers, so the
-/// code is requested lazily and can't expire before the password proof.
-#[allow(clippy::type_complexity)]
-pub(crate) fn spawn_login(
-    username: String,
-    password: String,
-) -> (
-    async_channel::Receiver<Result<(), String>>,
-    async_channel::Receiver<std::sync::mpsc::Sender<String>>,
-    async_channel::Receiver<(String, std::sync::mpsc::Sender<String>)>,
-) {
+/// runtime. The returned [`LoginChannels`] carry the final result and the lazy
+/// prompts. Each login closure blocks the worker on a sender the UI answers, so
+/// a code is requested lazily and can't expire before the password proof.
+pub(crate) fn spawn_login(username: String, password: String) -> LoginChannels {
    let (tx, rx) = async_channel::bounded(1);
    // Two, not one: a CAPTCHA-gated login restarts, so a 2FA account is asked
    // for a code on each attempt and a single slot would deadlock the worker.
    let (totp_req_tx, totp_req_rx) = async_channel::bounded(2);
    let (hv_req_tx, hv_req_rx) = async_channel::bounded(1);
+    let (mailbox_req_tx, mailbox_req_rx) = async_channel::bounded(1);
    std::thread::spawn(move || {
        let rt = match tokio::runtime::Builder::new_current_thread()
            .enable_all()
@@ -267,6 +298,19 @@ pub(crate) fn spawn_login(
                        .recv()
                        .map_err(|_| pdfs_core::Error::Other("two-factor entry cancelled".into()))
                },
+                |attempt| {
+                    let (answer_tx, answer_rx) = std::sync::mpsc::channel::<(String, bool)>();
+                    mailbox_req_tx
+                        .send_blocking((attempt, answer_tx))
+                        .map_err(|_| pdfs_core::Error::Other("mailbox prompt closed".into()))?;
+                    let (password, remember) = answer_rx
+                        .recv()
+                        .map_err(|_| pdfs_core::Error::Other("mailbox entry cancelled".into()))?;
+                    Ok(auth::Mailbox {
+                        password: password.into(),
+                        remember,
+                    })
+                },
                |hv| {
                    // Gated: hand the UI the page to show, block on the token the
                    // user earns by solving it.
@@ -287,7 +331,143 @@ pub(crate) fn spawn_login(
        });
        let _ = tx.send_blocking(result);
    });
-    (rx, totp_req_rx, hv_req_rx)
+    LoginChannels {
+        result: rx,
+        totp: totp_req_rx,
+        hv: hv_req_rx,
+        mailbox: mailbox_req_rx,
+    }
+}
+
+/// Ask for the mailbox password of a two-password account.
+///
+/// `done` gets the password and the "keep unlocked" choice, or `None` when the
+/// dialog was cancelled. `retry` says the last answer was wrong. The choice
+/// defaults to off: storing the mailbox unlock in the keyring trades away what
+/// a separate mailbox password is for, so it is something to opt into.
+pub(crate) fn ask_mailbox(
+    ui: &Rc<Ui>,
+    retry: bool,
+    done: impl FnOnce(Option<(String, bool)>) + 'static,
+) {
+    let body = if retry {
+        gettext("That mailbox password didn't unlock your account. Try again.")
+    } else {
+        gettext("This account has a separate mailbox password. Enter it to unlock your files.")
+    };
+    let dialog = adw::AlertDialog::builder()
+        .heading(gettext("Mailbox Password"))
+        .body(body)
+        .build();
+
+    let group = adw::PreferencesGroup::new();
+    let entry = adw::PasswordEntryRow::builder()
+        .title(gettext("Mailbox password"))
+        .activates_default(true)
+        .build();
+    let remember = adw::SwitchRow::builder()
+        .title(gettext("Keep unlocked on this computer"))
+        .subtitle(gettext(
+            "Stores the unlock in the system keyring, so Proton Drive opens without asking after every login. Otherwise you enter the password once per session.",
+        ))
+        .build();
+    group.add(&entry);
+    group.add(&remember);
+    dialog.set_extra_child(Some(&group));
+
+    dialog.add_response("cancel", &gettext("Cancel"));
+    dialog.add_response("unlock", &gettext("Unlock"));
+    dialog.set_response_appearance("unlock", adw::ResponseAppearance::Suggested);
+    dialog.set_default_response(Some("unlock"));
+    dialog.set_close_response("cancel");
+
+    let done = RefCell::new(Some(done));
+    dialog.connect_response(None, move |_, resp| {
+        let Some(done) = done.borrow_mut().take() else {
+            return;
+        };
+        let password = entry.text().to_string();
+        if resp == "unlock" && !password.is_empty() {
+            done(Some((password, remember.is_active())));
+        } else {
+            done(None);
+        }
+    });
+
+    let parent = ui_window(ui).map(|w| w.upcast::<gtk4::Window>());
+    dialog.present(parent.as_ref());
+}
+
+/// If the signed-in account is locked, ask for its mailbox password — once per
+/// run; after a cancel, a toast keeps an Unlock button within reach.
+///
+/// The key state is a keyring and kernel-keyring read, so it runs on a worker.
+pub(crate) fn offer_unlock(ui: &Rc<Ui>) {
+    if ui.unlock_offered.get() {
+        return;
+    }
+    let ui = ui.clone();
+    glib::spawn_future_local(async move {
+        let state = gio::spawn_blocking(|| auth::key_state().ok()).await;
+        if matches!(state, Ok(Some(auth::KeyState::Locked))) && !ui.unlock_offered.replace(true) {
+            prompt_unlock(&ui, false);
+        }
+    });
+}
+
+enum UnlockOutcome {
+    Unlocked,
+    Wrong,
+    Failed(String),
+}
+
+/// Ask for the mailbox password and unlock the account with it.
+fn prompt_unlock(ui: &Rc<Ui>, retry: bool) {
+    let ui_done = ui.clone();
+    ask_mailbox(ui, retry, move |answer| {
+        let Some((password, remember)) = answer else {
+            toast_action(
+                &ui_done,
+                &gettext("Proton Drive is locked. Enter your mailbox password to unlock it."),
+                &gettext("Unlock"),
+                |ui| prompt_unlock(ui, false),
+            );
+            return;
+        };
+        glib::spawn_future_local(async move {
+            // Verifying talks to Proton and the restart talks to systemd, so
+            // both run on a worker, never on the main loop.
+            let outcome = gio::spawn_blocking(move || {
+                let rt = match tokio::runtime::Builder::new_current_thread()
+                    .enable_all()
+                    .build()
+                {
+                    Ok(rt) => rt,
+                    Err(e) => return UnlockOutcome::Failed(e.to_string()),
+                };
+                match rt.block_on(auth::unlock(&password, remember)) {
+                    Ok(()) => {
+                        service::restart();
+                        UnlockOutcome::Unlocked
+                    }
+                    Err(pdfs_core::Error::WrongMailboxPassword) => UnlockOutcome::Wrong,
+                    Err(e) => UnlockOutcome::Failed(login_error_message(&e)),
+                }
+            })
+            .await;
+            match outcome {
+                Ok(UnlockOutcome::Unlocked) => {
+                    toast(&ui_done, &gettext("Unlocked."));
+                    refresh(&ui_done);
+                }
+                Ok(UnlockOutcome::Wrong) => prompt_unlock(&ui_done, true),
+                Ok(UnlockOutcome::Failed(message)) => {
+                    toast_error(&ui_done, &gettext("Couldn't unlock"), &message)
+                }
+                Err(_) => {}
+            }
+        });
+    });
 }

 /// Show the lazy two-factor dialog and feed the entered code back to the waiting
@@ -374,6 +554,12 @@ mod tests {
        assert!(login_error_message(&hv).contains("verification wasn't completed"));
    }

+    #[test]
+    fn a_cancelled_mailbox_prompt_is_reported_as_such() {
+        let error = pdfs_core::Error::Other("mailbox entry cancelled".into());
+        assert!(login_error_message(&error).contains("no mailbox password"));
+    }
+
    #[test]
    fn an_unmapped_error_keeps_its_text() {
        let error = pdfs_core::Error::Other("something odd".into());
@@ -618,6 +618,7 @@ pub(crate) fn shared_item_as_entry(item: &SharedItem) -> DirEntry {
        shared_by_unverified: false,
        trashed_at: 0,
        trashed_from: None,
+        issue: None,
    }
 }

@@ -860,6 +860,7 @@ pub(crate) fn refresh(ui: &Rc<Ui>) {
        }
    }

+    offer_unlock(ui);
    refresh_status(ui);
    refresh_transfers(ui);
 }
@@ -1069,7 +1070,11 @@ pub(crate) fn repaint_transfers(ui: &Rc<Ui>, items: &[TransferItem], jobs: &[Job
            let row_box = gtk4::Box::new(gtk4::Orientation::Vertical, 4);
            row_box.set_margin_top(8);
            row_box.set_margin_bottom(8);
-            let label = gtk4::Label::builder().halign(gtk4::Align::Start).build();
+            // Ellipsized so a long file name cannot widen the page.
+            let label = gtk4::Label::builder()
+                .halign(gtk4::Align::Start)
+                .ellipsize(gtk4::pango::EllipsizeMode::Middle)
+                .build();
            label.add_css_class("dim-label");
            let bar = gtk4::ProgressBar::new();
            row_box.append(&label);
@@ -533,6 +533,7 @@ mod tests {
            shared_by_unverified: false,
            trashed_at,
            trashed_from: from.map(str::to_string),
+            issue: None,
        }
    }

@@ -133,7 +133,7 @@ impl Drop for Busy {
 /// from Shared or Shared-with-me may not: it can live under a device folder's
 /// own inode space, or on someone else's volume, neither of which the primary
 /// mount's path space can name. Those carry a uid instead, and the daemon
-/// resolves it with `Core::resolve_anywhere` (mount-architecture.md P4).
+/// resolves it with `Core::resolve_anywhere`.
 ///
 /// The two are separate request variants rather than one request with an
 /// optional field on purpose: an older daemon that ignored `uid` would resolve
@@ -535,6 +535,12 @@ async fn mounted_target_within(mountpoint: PathBuf, hit: SearchHit) -> Option<Pa
 }

 impl Ui {
+    /// `--preload`: create the surface, renderer and style state now, without
+    /// mapping the window, so the first real summon only has to present it.
+    pub(crate) fn preload(&self) {
+        WidgetExt::realize(&self.window);
+    }
+
    /// Reset and present the resident prompt in response to GApplication
    /// activation. A second invocation while a file is materialising merely
    /// raises the progress window; it must not make the in-flight open mutable.
@@ -166,6 +166,15 @@ fn poll_state(socket: &Path, default_mountpoint: &Path) -> DriveState {
        // No daemon: describe login state instead so the menu is still useful.
        Err(_) => {
            let (line, phase) = match auth::load() {
+                Ok(s) if matches!(auth::key_state(), Ok(auth::KeyState::Locked)) => (
+                    // Translators: {username} is the Proton account name. The
+                    // account has a mailbox password that has to be entered.
+                    gettext_f(
+                        "Signed in as {username} — locked",
+                        &[("username", &s.username)],
+                    ),
+                    Phase::Attention,
+                ),
                Ok(s) => (
                    // Translators: {username} is the Proton account name.
                    gettext_f(
@@ -268,6 +268,9 @@ Options:
                        every keystroke — results appear as you type, unlike
                        --dmenu. Also settable as \"prompt\": { \"mode\": \"fzf\" }.
  --gtk                 Force the built-in window, overriding that setting.
+  --preload             Start the built-in window hidden and stay resident, so
+                        the first summon opens at once. For session autostart;
+                        does nothing if the prompt is already running.
  --menu <COMMAND>      Launcher command line for --dmenu, e.g.
                        --menu 'fuzzel --dmenu --width 60'. Overrides
                        \"prompt\": { \"menu\": [...] }.
@@ -293,6 +296,8 @@ struct Args {
    feed: Option<Option<String>>,
    /// `--inner`: we are the process a spawned terminal is running.
    inner: bool,
+    /// `--preload`: become the resident GTK instance without showing it.
+    preload: bool,
 }

 fn parse_args(argv: impl Iterator<Item = String>) -> Result<Args, String> {
@@ -302,6 +307,7 @@ fn parse_args(argv: impl Iterator<Item = String>) -> Result<Args, String> {
        query: None,
        feed: None,
        inner: false,
+        preload: false,
    };
    let mut argv = argv.peekable();
    while let Some(arg) = argv.next() {
@@ -310,6 +316,7 @@ fn parse_args(argv: impl Iterator<Item = String>) -> Result<Args, String> {
            "--fzf" => args.mode = Some(PromptMode::Fzf),
            "--gtk" => args.mode = Some(PromptMode::Gtk),
            "--inner" => args.inner = true,
+            "--preload" => args.preload = true,
            // fzf passes an empty argument for an empty input, so a missing
            // value here is that case rather than a user error.
            "--feed" => args.feed = Some(argv.next().filter(|text| !text.trim().is_empty())),
@@ -337,6 +344,13 @@ fn parse_args(argv: impl Iterator<Item = String>) -> Result<Args, String> {
            other => return Err(format!("unrecognised argument: {other}")),
        }
    }
+    // Only the GTK window has a resident process worth warming up.
+    if args.preload {
+        if matches!(args.mode, Some(PromptMode::Dmenu | PromptMode::Fzf)) || args.query.is_some() {
+            return Err("--preload only applies to the built-in window".to_string());
+        }
+        args.mode = Some(PromptMode::Gtk);
+    }
    Ok(args)
 }

@@ -398,9 +412,31 @@ fn main() -> glib::ExitCode {
    // GtkApplication normally remains active while it owns a window, including
    // when that window is hidden. Hold it explicitly as well: residency is a
    // product requirement here, not an incidental window-lifetime side effect.
-    let _resident = app.hold();
-    app.connect_startup(|_| theme::load_resources("/de/nils/protondrivelinux/prompt.css"));
+    // Only the primary instance runs startup; a hold taken before registration
+    // would also keep every remote invocation alive after it has forwarded
+    // its activation.
+    let resident = Rc::new(RefCell::new(None));
+    app.connect_startup(move |app| {
+        *resident.borrow_mut() = Some(app.hold());
+        theme::load_resources("/de/nils/protondrivelinux/prompt.css");
+    });
+    if args.preload {
+        if let Err(e) = app.register(gtk4::gio::Cancellable::NONE) {
+            eprintln!("pdfs-prompt: {e}");
+            return glib::ExitCode::FAILURE;
+        }
+        // Another instance is already resident; activating it would show it.
+        // Dropping a registered application that never ran makes GIO warn
+        // about the D-Bus registration, so leave it to process exit.
+        if app.is_remote() {
+            std::mem::forget(app);
+            return glib::ExitCode::SUCCESS;
+        }
+    }
    let prompt: Rc<RefCell<Option<Rc<hud::Ui>>>> = Rc::new(RefCell::new(None));
+    // The first activation of a preloading instance is its own startup, not a
+    // summon: build the window but leave it hidden.
+    let quiet = std::cell::Cell::new(args.preload);
    app.connect_activate(move |app| {
        let ui = if let Some(ui) = prompt.borrow().clone() {
            ui
@@ -411,6 +447,10 @@ fn main() -> glib::ExitCode {
            *prompt.borrow_mut() = Some(ui.clone());
            ui
        };
+        if quiet.replace(false) {
+            ui.preload();
+            return;
+        }
        ui.activate();
    });
    // GTK must not try to parse our own flags; they were consumed above.
@@ -582,4 +622,16 @@ mod tests {
        let args = parse(&["--dmenu", "--query", "tax return 2024"]).unwrap();
        assert_eq!(args.query.as_deref(), Some("tax return 2024"));
    }
+
+    #[test]
+    fn preload_forces_the_gtk_window_and_rejects_the_launchers() {
+        let args = parse(&["--preload"]).unwrap();
+        assert!(args.preload);
+        assert_eq!(args.mode, Some(PromptMode::Gtk));
+
+        assert!(parse(&["--preload", "--dmenu"]).is_err());
+        assert!(parse(&["--fzf", "--preload"]).is_err());
+        assert!(parse(&["--preload", "--menu", "fuzzel --dmenu"]).is_err());
+        assert!(parse(&["--preload", "--query", "tax"]).is_err());
+    }
 }
@@ -11,6 +11,415 @@ scratch (user data in `staging/` and `recovery/` is never touched by this).

 ## [Unreleased]

+## [3.1.0] — 2026-10-07
+
+Schema: **42**, unchanged.
+
+### Added
+- **Two-password accounts.** An account with a separate mailbox password now signs in: the app
+  and `pdfs login` ask for it after the login password and check it against the account, so a
+  typo is a retry and not a daemon that never mounts. The mailbox password is never stored.
+  What it unlocks is kept in kernel memory for the login session, so it is asked for once per
+  session and is gone after a reboot or when you log out of the machine.
+- **`pdfs unlock` and `pdfs lock`.** `pdfs unlock` enters the mailbox password of a locked
+  account and starts the daemon's mount; `pdfs lock` forgets it again. `--remember` on `login`
+  and `unlock` (and the "Keep unlocked on this computer" switch in the app) keeps the unlock in
+  the system keyring instead, so the daemon starts without asking; `pdfs lock --forget` removes
+  it. Off by default: it gives up the separation a second password is for.
+- **Locked state.** `pdfs status`, `pdfs diagnose` and the tray say when the account is waiting
+  for its mailbox password, and the app asks for it when it opens.
+
+### Changed
+- **The keyring no longer holds a password.** The session blob keeps the keys' passphrases
+  instead of the mailbox password, and a blob written by 3.0.x is converted on the first start.
+  A stored password the account rejects (a two-password account that was signed in with only
+  its login password) leaves the account locked instead of failing every start.
+- **The daemon is not dumpable.** It holds the unlock in memory, so core dumps and same-user
+  `ptrace` are off for it.
+- **The offline cache is re-keyed** from the new secret, so the first start after the update
+  reads it as cold and fetches the tree again once.
+
+### Fixed
+- **systemd killed a daemon that was only retrying.** `WatchdogSec` was answered only once a
+  mount existed, so a daemon waiting for a login or retrying a failed mount was aborted after
+  two minutes and restarted in a loop, hiding the error it logged. It now answers the watchdog
+  while it waits. ([#26](https://github.com/narrrl/proton-drive-linux/issues/26))
+- **A refreshed token could overwrite a newer unlock or revive a signed-out session.** Token
+  rotation now updates only the tokens in the stored blob.
+
+## [3.0.0] — 2026-10-05
+
+Schema: **42**. The queue table is rebuilt so an id is never given out twice; queued changes
+are kept. Queued changes get a column for the reason Drive refused them, and two for the
+content a new file was sent with and where, and name their file and folder by local id as well
+as by Drive's id. Stored files and folders name their parent
+folder by local id too. A file or folder made on this machine that Drive does not have yet goes
+by its local id, in the queue, the stored tree and pins alike.
+
+### Added
+- **Sync issues.** A change Drive refuses because the storage is full, access was taken away,
+  its folder is gone, a folder limit is reached or Drive rejected it shows up at once as needing
+  attention, with what it means and what to do, instead of after six failed attempts. The
+  change stays queued and is still retried.
+- **Export a queued file.** The Sync page's Export button and `pdfs sync export <id> <dest>`
+  save a copy of a queued upload's content. The upload stays queued.
+- **`pdfs sync issues`** lists the changes that need attention; `pdfs sync queue` shows the
+  issue next to each change.
+- **Discard a queued change.** The Sync page's Discard button and `pdfs sync discard <id>` drop
+  a change Drive will not take and undo it here: a new file or folder goes, anything else goes
+  back to what Drive has. Export a file first to keep its content.
+- **Sync issues show on the file.** A file or folder with a change Drive refused carries a
+  warning badge in the file browser, and its tooltip says what it means and what to do.
+
+### Changed
+- **Making, renaming and deleting through the mount no longer waits for Drive.** A new folder,
+  a new file, a rename or a delete is recorded locally and the call returns at once; the queue
+  sends it, as it does offline. `"local_first": false` in `config.json` brings back the old way
+  for this release.
+- **The queue sends up to 16 changes at once instead of 3.** A thousand new files in a hundred
+  folders reach Drive about three times as fast on a LAN, and four times as fast on Wi-Fi.
+
+### Fixed
+- **A file made under the name of a file whose upload is still going out keeps its name.** It
+  no longer lands as a conflict copy, and the mount no longer shows that copy's name (B154).
+- **A change to a file no longer lands as a conflict copy of itself when the link loses Drive's
+  answer to its upload** (B155).
+- **A file written again while its upload was being retried no longer lands as a conflict copy
+  of itself when the link lost Drive's answer to the first try** (B156).
+- **Writing to a file twice in a row no longer fails with "Input/output error" when the link
+  lost Drive's answer to reading back the file's last upload** (B157).
+- **A file renamed twice in a row, while the first name was still taken, keeps the second name**
+  (B158).
+- **Opening a file right after the daemon restarts no longer fails with "Resource temporarily
+  unavailable"** (B159).
+- **A new folder, or a new empty file, reaches Drive at once**, not up to half a minute later
+  (B160, B192).
+- **A file moved while it was still being uploaded keeps its new name in the mount** on a slow
+  link (B161).
+- **A folder removed and made again at once keeps what goes into it.** It used to be created
+  inside the removed folder and was trashed along with it (B162).
+- **A new file no longer reads as empty just after it is uploaded.** Drive can list it a moment
+  before its contents are committed, and the mount took that answer (B163).
+- **A folder no longer lists a new file twice while it is uploaded.** A listing taken as the
+  upload landed showed it both as Drive had it and as the queue did (B164).
+- **Stopping the daemon no longer hangs until systemd kills it.** A stop waits up to 10 s for
+  work in progress, then exits and logs what was still running (B165).
+- **A folder no longer drops or empties a new file while others are uploaded.** A file whose
+  upload landed while the folder was being listed was missing from that listing, or listed as
+  empty (B166).
+- **The mount comes up faster on a large Drive.** Rebuilding the folder listings from the cache
+  took close to 2 s with 37,000 files at every start (B167).
+- **Files deleted with their folder while uploading stay deleted.** The mount no longer tries
+  to upload them to the top of your Drive instead (B168).
+- **Stopping the daemon during a folder sync no longer waits for the sync.** The uploads in
+  progress finish, and the rest waits for the next start (B169).
+- **Writing to a file again just as its upload finishes no longer fails.** A write right after
+  it failed with "Input/output error" (B170).
+- **A file deleted while its upload was retrying is removed from Drive right away.** It no
+  longer waits for the upload's next retry (B171).
+- **A file deleted just as it reached Drive is removed from Drive too.** It no longer stayed
+  there, and the next file with that name no longer became a conflict copy (B173).
+- **Renaming a file just as it reaches Drive no longer fails with "Permission denied"**
+  (B174).
+- **A file replaced by a rename just as it reached Drive is removed from Drive too.** It no
+  longer stayed there, and the next rename of its name no longer moved it instead (B175).
+- **A write closed just as its file reached Drive is no longer lost** (B176).
+- **Opening a folder just as it reaches Drive no longer fails with "Input/output error"**
+  (B177).
+- **Deleting a folder while sync is paused no longer leaves a queued change behind** for a
+  file in it that was never uploaded (B178).
+- **A file read just as it reaches Drive no longer reads empty** (B179).
+- **Stopping the daemon no longer takes 10 seconds more than it needs** when an idle upload
+  worker missed the stop (B180).
+- **A folder made while offline or with sync paused no longer fails with "Input/output
+  error"** once it is refreshed or the connection comes back (B125).
+- **The daemon no longer hangs when a file being read changes on Drive** (B130).
+- **The Activity page says in your language why an edit was kept as a conflicting copy**,
+  instead of the daemon's English (B181).
+- **A file written after a restart no longer lands as a conflict copy of itself** when the
+  connection dropped just as it first reached Drive (B182).
+- **A file deleted after a restart is removed from Drive too** when the connection lost Drive's
+  answer to its upload and the file was written again meanwhile. It no longer stayed there and
+  turned the next file under its name into a conflict copy (B183).
+- **A file renamed while the connection lost Drive's answer to its upload lands once.** It no
+  longer stayed on Drive under its old name too, or, when deleted, under its old name alone
+  (B184).
+- **A new file written again just as it starts uploading no longer waits out a retry** before
+  it reaches Drive (B185).
+- **A file deleted while open can still be read and written until it is closed**, offline too.
+  A write into it no longer failed with "Input/output error" (B186).
+- **An uploaded file no longer leaves a copy of itself in the cache** until the next start
+  (B187).
+- **Changes that failed during a short outage go out soon after the connection is back**, not
+  after a retry delay of up to five minutes (B189).
+- **A file saved just before the daemon stops reaches Drive** with what was written. It could
+  keep its old content, or stay empty (B190).
+- **A file renamed just as its upload finished keeps its new name.** The mount no longer showed
+  the old name, and a second rename no longer failed with "No such file or directory" (B152,
+  B172).
+- **A change that waits for a name to be freed no longer waits seconds after it is.** A rename or
+  upload over a file being deleted goes out as soon as the delete lands (B153).
+- **A file deleted right after it was made no longer stays on Drive when the link lost Drive's
+  answer.** The node Drive made is trashed (B151).
+- **A new file no longer lands twice when the link loses Drive's answer to its upload.** The
+  file Drive made is taken as it is, instead of a second upload as a conflict copy (B127).
+- **A change to a file deleted elsewhere, together with its folder, no longer retries forever.**
+  The conflict copy that keeps it now lands in the location's root (B150).
+- **`pdfs rename` and `pdfs move` right after a change through the mount are no longer undone.**
+  They are queued behind it, and they work on a file that has not reached Drive yet (B149).
+- **A folder kept offline before it reached Drive stays kept offline.** Its pin was lost when the
+  folder landed (B148).
+- **A queued change no longer holds up the queue forever on a link that stops answering.**
+  Sending a new folder, a delete or a file waits at most 20 seconds for Drive, plus time for
+  the file's size, and then the queue treats the link as down and tries again.
+- **A file deleted while its first upload is on the wire no longer stays on Drive.** The node
+  the upload made is trashed as soon as it lands, so its name is free again (B129).
+- **A delete queued while a rename is sent is no longer lost.** The rename landing could remove
+  the delete from the queue, leaving the file on Drive (B137).
+- **A file made offline over one deleted offline is no longer lost.** Its upload could take
+  over the deleted file, and the delete then took the new bytes along with it (B128).
+- **A file deleted while its upload is on the wire no longer comes back as a `recovered-…`
+  copy** when another file is made right after (B133).
+- **A file made where another one is leaving no longer lands as a conflict copy.** Its upload
+  waits for the rename or trash that frees the name (B126, B138).
+- **A file closed just as its first upload lands keeps its last write.** The write was refused
+  and left in staging (B139).
+- **Files made in a new folder are still there after a restart.** A folder that landed as the
+  daemon stopped, or one listed from Drive while files in it were queued, came back empty
+  (B132, B140).
+- **A file renamed twice in quick succession ends up under the second name.** The first rename
+  could land after the second and undo it (B141).
+- **Renaming a new file just as its upload lands no longer fails with "Device or resource
+  busy".** The rename goes to the file Drive made (B142).
+- **A file whose upload landed just as the connection dropped no longer gets a conflict copy at
+  its next save.** The daemon reads the file back once the connection returns (B143).
+- **A rename whose target name was just freed no longer lands as a conflict copy.** The rename
+  is sent once more under the name it asked for (B144).
+- **Saving a download under its final name no longer fails with "Device or resource busy".**
+  A file made a moment before was taken for deleted and dropped from the queue (B145).
+- **A file renamed just as its upload lands keeps its new name.** The tree could take back the
+  name Drive still had (B146).
+- **A new file made under a name another file just left no longer takes that file's place on
+  Drive.** Both could land on one node, and one file's content was lost (B147).
+
+## [2.10.0] — 2026-10-03
+
+Schema: **36**. Every node row gets a local id that never changes; existing rows keep their
+row number as that id. Going back to 2.9 means rebuilding the cache. Requires `proton-drive-rs`
+**0.7.2**.
+
+### Added
+- **Migration tests on real databases.** A database 2.8.2 wrote, with queued changes due,
+  parked, failing, waiting for access and in flight, migrates with every change intact.
+  `PDFS_MIGRATE_DB=<path> cargo test -p pdfs-core a_copy_of_a_real_database -- --ignored` runs
+  the same check on a read-only copy of any database.
+
+### Changed
+- **A file keeps its inode number across daemon restarts.** Inodes are now the node's local id
+  instead of a counter that started over on every run.
+- **Every mount serves from one tree.** An on-demand sync folder used to keep its own copy of the
+  nodes it showed, which background work had to visit one by one and could miss (B74). It now
+  shares the tree with My files; only the root it starts at is its own.
+
+### Fixed
+- **A file renamed or moved while its first upload is on the wire keeps its new name and folder.**
+  It landed under the old name and the rename was lost (B136).
+
+## [2.9.0] — 2026-10-03
+
+Schema: **35** (unchanged). Requires `proton-drive-rs` **0.7.2**.
+
+### Added
+- **Seeded simulation runs.** `cargo test -p pdfs-fuse --lib sim:: -- --ignored
+  --test-threads=1` mounts one or more real FUSE daemons against an in-memory Drive that lags,
+  drops, reorders and echoes like the real one. Each seed draws syscalls, link flaps and restarts,
+  checks every answer against a POSIX model, and at the end checks that nothing was lost and the
+  clients converged. CI runs them on pushes to main. They found B122 to B135.
+- **More acceptance cases.** Regressions for B48, B80, B86, B88, B94, B95, B98, B102, B111, B113
+  and B114 to B121, and a check that `pdfs` output into a closed pipe stays quiet. The console
+  report has one line per case and a summary table, and `--journal-check` also fails on a
+  conflict copy, a FUSE job held for long, or an authority re-read.
+
+### Fixed
+- **A new file moved or renamed before its first upload no longer lands as a conflict copy**
+  next to its own empty original (B113).
+- **`pdfs rm`, `pdfs rename` and `pdfs mkdir` take paths in on-demand folders.** They answered
+  "is not under the mountpoint" for a path `pdfs move` took. `rm` and `rename` refuse a path that
+  names a mount's root (B88).
+- **`pdfs ls | head` no longer panics** with "Broken pipe". A closed stdout exits 0; any other
+  write error exits 1.
+- **A file removed, renamed or moved with `pdfs` stops resolving under its old name at once**,
+  instead of for up to 30 seconds (B114).
+- **`pdfs ls` and the app's file browser show a file's real size**, not its encrypted one
+  (B115).
+- **Trashing a folder also drops the creates queued in its subfolders.** One could stay queued
+  with its bytes, or land in the root (B116).
+- **An upload queued for a file `pdfs move` moved keeps its path** in `pdfs sync queue` and is
+  no longer put off once after the resume (B117).
+- **Creating a file or folder through the mount no longer fails with `ENOENT`** when Drive is
+  slow to list what it made. The mount asks again, and queues the create if it still cannot see
+  it (B118).
+- **A file just written can be read without the network.** Its uploaded bytes stay cached, and
+  `pdfs status` counts the upload as pending until they are (B119).
+- **A file queued inside a folder that just landed is no longer put off** for five seconds
+  (B120).
+- **A move right after a rename lands.** It failed with `Input/output error` through the mount
+  and with "out of date" from `pdfs move`, and a rename across folders took up to 10 seconds
+  (B111, B121).
+- **A rename across folders no longer fails with `Input/output error`** when the source folder
+  holds the new name (B122).
+- **A second write open on a file just written no longer fails** with `Input/output error`
+  (B123).
+- **After a replacing rename fails, the file it was replacing stays in the mount** (B124).
+- **A write to a file whose create could not be read back no longer lands as a conflict copy**
+  (B131).
+- **A file just moved is found by its new path.** A lookup right after the rename could miss it
+  (B135).
+
+### Notes
+- The simulation runs found bugs that are still open: B125 to B130 and B132 to B134 in
+  `docs/BUGS.md`. The worst are B127 and B128 (a file created offline can land twice, or be lost
+  when created over one deleted offline), B129 (a file deleted while its create is on the wire
+  stays on Drive) and B130 (a read that a remote change invalidates can hang the daemon).
+
+## [2.8.2] — 2026-10-01
+
+Schema: **35** (unchanged). Requires `proton-drive-rs` **0.7.2**.
+
+### Fixed
+- **Folders shared with you no longer go missing when one person shared several.** When
+  several accepted shares came from the same owner's volume, only the first appeared under
+  Shared with me, and the rest were skipped with `missing key`. `proton-drive-rs` 0.7.2 resolves
+  each shared root with its own key (B112, #25).
+
+## [2.8.1] — 2026-09-30
+
+Schema: **35** (unchanged). Requires `proton-drive-rs` **0.7.1**.
+
+### Fixed
+- **The service no longer starts before the desktop session.** `proton-drive.service` was
+  wanted by `default.target`, which is reached before the desktop hands `DISPLAY` /
+  `WAYLAND_DISPLAY` to the user's systemd. The first keyring call then started the Secret
+  Service without a display; on KDE `ksecretd` crashed at every login and the first start of the
+  service failed. The unit is now wanted by `graphical-session.target`. Existing installs switch
+  over on the next sign-in or "Start on login" toggle, or with
+  `systemctl --user reenable proton-drive.service` (#23).
+
+## [2.8.0] — 2026-09-30
+
+Schema: **35** (unchanged). Requires `proton-drive-rs` **0.7.1**.
+
+### Added
+- **`pdfs trash --json`** prints the trash listing as JSON.
+- **The FUSE acceptance suite tests the signed-in account by default.**
+  `scripts/fuse-acceptance.sh` with no arguments creates test folders in My files and new
+  on-demand and mirror sync folders, runs every case in each, and removes all of it afterwards,
+  also on a failure or interrupt. A run that dies is cleaned up by the next one. New cases cover
+  block boundaries, unusual names, a deep tree, a wide directory, rename patterns, handle coherency,
+  throughput and B100. `--offline-only` runs the account-free suite as before.
+
+### Changed
+- **The mount keeps working through a network drop.** When Drive stops answering, the daemon
+  now marks itself offline within about 20 seconds instead of failing every call for up to two
+  minutes. While offline, creating, renaming and deleting files and folders is queued instead of
+  failing with `Input/output error`, folders list from the local cache, and a read that needs
+  data from Drive waits up to 30 seconds for the connection. The daemon checks every few seconds
+  for the connection to return, then uploads the queued changes. A file whose creation timed
+  out but reached Drive anyway is taken over rather than uploaded again as a conflict copy.
+- **A dead connection is noticed sooner.** `proton-drive-rs` 0.7.1 sends TCP keepalives, so a
+  connection that died silently fails instead of waiting for its request timeout.
+
+### Fixed
+- **Truncating and then writing past the end no longer brings old bytes back.** The gap
+  between the new end and the write now reads as zeros, as it should, instead of the file's
+  earlier content. When that earlier content had not been uploaded yet, the file failed with
+  `Input/output error` and its upload retried forever (B101).
+- **A write made while a new file is first uploading is no longer lost.** Drive could keep an
+  empty or older copy of a file written right after it was created, and closing a file held open
+  across its first upload could fail (B101).
+- **Removing a folder also cancels the pending uploads of the files inside it.** Before, an
+  edit that had not reached Drive yet kept retrying against the trash forever and kept its
+  staged copy on disk. `pdfs rm` now also drops what was queued for what it removes (B102).
+- **A program reading a file keeps its data when another program replaces the file.** Saving
+  over a file by renaming a new copy onto it (what most editors and `os.replace` do) made
+  reads through handles already open on the old file fail with `Input/output error` (B104).
+- **Short-lived files no longer come back as conflict copies.** A file deleted right after it
+  was written, such as a SQLite journal, could be uploaded as a `recovered-…` conflict copy in
+  the Drive root (B105).
+- **Editors can save over a file several times in a row.** The fix for B104 could leave the
+  upload of a replaced file queued, and the next save onto the same name failed with
+  `Input/output error` (B106).
+- **Renaming a file back right after renaming it no longer fails.** Drive can briefly call the
+  second rename out of date, and the daemon now waits it out instead of returning an I/O error
+  (B111).
+- **Reading a freshly listed file no longer hangs.** When a read had to fetch the file's real
+  size first, the daemon could wait on the read it was serving, and the program froze until
+  the daemon restarted (B110).
+- **Databases and other files kept open while written no longer read back empty.** When the
+  folder was listed again while a file was still open, its size dropped to what Drive held,
+  often 0 bytes, and SQLite reported `database disk image is malformed` (B109).
+- **Deleting files during a mirror pass no longer marks the folder as failed.** A file removed
+  after the pass planned its upload was counted as an error, so the folder showed `error` until
+  a later pass (B108).
+- **A read no longer hangs when the connection stalls.** A read that gets no answer from Drive
+  within two minutes now fails with `Input/output error` instead of blocking the program for
+  as long as half an hour (B107).
+- **The trash no longer freezes after a server call hangs.** Until the daemon restarted, the
+  trash kept showing the same entries, and a folder just deleted could not be found there to
+  delete permanently (B103).
+- **Freshly listed files read correctly.** A file whose real size had not been fetched yet
+  reported its encrypted size, about 53 bytes too big, and reading it failed with
+  `Input/output error`. This happened most often right after copying a large folder. Reads and
+  write opens now fetch the real size first, and a big folder walk no longer skips size lookups
+  (B100).
+
+## [2.7.0] — 2026-09-29
+
+Schema: **35** (unchanged).
+
+### Added
+- **Moves between locations without transferring content.** `pdfs move` and the app's
+  **Move to…** now take a file or folder from My files into a synced folder, or between two
+  synced folders, on-demand or mirrored. The move happens on Proton Drive, so nothing is
+  downloaded or uploaded again. `mv` between two locations still copies, because the kernel
+  refuses a rename between two mounts. The app's Move dialog lists every location at its top
+  level. A move is refused, with the reason, when the source still has changes that are not on
+  Proton Drive, when the two locations are on different volumes, or when a synced folder stays
+  busy with a sync pass.
+- **`pdfs move` takes several sources.** `pdfs move a b c DEST` moves all three and
+  reports each one that could not move.
+- **Moving into a mirrored folder reuses cached content.** A file already cached by
+  an online-only folder is copied into place instead of downloaded again.
+
+### Changed
+- **New project homepage: [proton-drive.narl.io](https://proton-drive.narl.io).** The About
+  dialog's website link, the README, and the package metadata (Cargo, PKGBUILDs, `.deb`,
+  `.rpm`) point there. The source code link stays on GitHub.
+
+## [2.6.2] — 2026-09-28
+
+Schema: **35** (unchanged).
+
+### Fixed
+- **Photos remembers the Albums and Places views.** Leaving Photos from Albums or Places and
+  coming back showed the timeline while the Albums or Places toggle stayed selected. The page
+  now reopens on the selected view, and Places keeps its Grid or Map layout.
+- **The Sync page keeps a steady width.** A long file name in Transfers no longer widens the
+  page. Overview and Folders now fill the width next to the sidebar.
+
+## [2.6.1] — 2026-09-28
+
+Schema: **35** (unchanged).
+
+### Added
+- **`pdfs-prompt --preload`.** Starts the launcher hidden, for session autostart such as
+  Hyprland's `exec-once`, so the first shortcut opens it as fast as later ones. It does nothing
+  when the launcher is already running.
+
+### Fixed
+- **Launcher invocations no longer pile up.** Each shortcut press after the first used to leave
+  a `pdfs-prompt` process behind after handing the request to the running launcher. It now exits.
+
 ## [2.6.0] — 2026-09-28

 The search launcher (`pdfs-prompt`) is rebuilt around a preview pane, and it now looks like the
@@ -1226,6 +1635,17 @@ First stable release: FUSE files-on-demand mount, sync daemon under `proton-driv
 - The outstanding FUSE defects tracked in `docs/BUGS.md`, plus a truncate defect, validated
  by a new POSIX compliance suite for the filesystem.

+[3.0.0]: https://github.com/narrrl/proton-drive-linux/releases/tag/v3.0.0
+
+[2.10.0]: https://github.com/narrrl/proton-drive-linux/releases/tag/v2.10.0
+[2.9.0]: https://github.com/narrrl/proton-drive-linux/releases/tag/v2.9.0
+[2.8.2]: https://github.com/narrrl/proton-drive-linux/releases/tag/v2.8.2
+[2.8.1]: https://github.com/narrrl/proton-drive-linux/releases/tag/v2.8.1
+[2.8.0]: https://github.com/narrrl/proton-drive-linux/releases/tag/v2.8.0
+[2.7.0]: https://github.com/narrrl/proton-drive-linux/releases/tag/v2.7.0
+
+[2.6.2]: https://github.com/narrrl/proton-drive-linux/releases/tag/v2.6.2
+[2.6.1]: https://github.com/narrrl/proton-drive-linux/releases/tag/v2.6.1
 [2.6.0]: https://github.com/narrrl/proton-drive-linux/releases/tag/v2.6.0
 [2.5.0]: https://github.com/narrrl/proton-drive-linux/releases/tag/v2.5.0
 [2.4.0]: https://github.com/narrrl/proton-drive-linux/releases/tag/v2.4.0
@@ -53,7 +53,7 @@ talks to the running service (`proton-drive.service`); `login`, `logout`, `mount
 | `pdfs search QUERY [--in FOLDER] [--limit N]` | Search names in the local index. |
 | `pdfs mkdir PARENT NAME` | Create a folder. |
 | `pdfs rename PATH NEW_NAME` | Rename a file or folder. |
-| `pdfs move PATH NEW_PARENT` | Move into another folder. |
+| `pdfs move PATH... NEW_PARENT` | Move one or more files or folders into another folder. The two may be in different locations (My files, an on-demand or a mirrored synced folder); the move happens on Proton Drive, without downloading or uploading anything. |
 | `pdfs rm PATH` | Move to the Trash. |
 | `pdfs upload SOURCES... [-t FOLDER]` | Upload local files and folders (recursively) in the background. Follow with `pdfs transfers`. |
 | `pdfs refresh [TARGET] [--full]` | Forget a cached listing so the next read fetches it again. `TARGET` is a folder, `trash` or `photos`; `--full` with `photos` re-reads every photo's metadata. |
@@ -82,6 +82,9 @@ commands are for scripts and for cases where the mount is not available.
 | `pdfs sync resume [--folder ID]` | Resume after a pause. |
 | `pdfs sync limit [--up RATE] [--down RATE]` | Cap bandwidth, for example `500K` or `2M` per second. `0` removes a cap. Without options, prints the current caps. |
 | `pdfs sync queue` | List changes that have not reached Proton Drive yet. |
+| `pdfs sync issues` | List queued changes Proton Drive refused or that keep failing, and what to do. |
+| `pdfs sync export ID DEST` | Save a copy of a queued upload's content. `DEST` may be a folder; an existing file is never overwritten. The upload stays queued. |
+| `pdfs sync discard ID [--yes]` | Drop a queued change and undo it here: a new file or folder goes, anything else goes back to what Proton Drive has. Content not exported first is lost. |
 | `pdfs sync retry [ID]` | Retry one queued operation, or every failed one. |
 | `pdfs sync restore [--device UID] [--yes]` | Re-attach this computer's backed-up folders to local folders and download them. `--device` restores another computer's folders. See [RECOVERY.md](RECOVERY.md). |

@@ -177,7 +180,7 @@ commands are for scripts and for cases where the mount is not available.
 ## Scripting with `--json`

 The global `--json` flag makes query commands print JSON: `status`, `ls`, `pins`, `sync list`,
-`devices list`, `locations`, `transfers`, `activity` and `cache inspect`. Commands that change
+`devices list`, `locations`, `transfers`, `activity`, `trash` and `cache inspect`. Commands that change
 something keep their human-readable output; check their exit code.

 ```bash
@@ -38,7 +38,7 @@ Inside `content/`:
 > not reached Proton Drive and exists nowhere else.

 Everything in these directories except the keyring is **decrypted**. See
-[ARCHITECTURE.md §8](ARCHITECTURE.md#8-threat-model-what-this-client-writes-to-disk-in-plaintext).
+[ARCHITECTURE.md §10](ARCHITECTURE.md#10-threat-model-what-this-client-writes-to-disk-in-plaintext).

 ## `config.json`

@@ -80,6 +80,7 @@ fix it.
 | `ignore_patterns` | list | see below | — | Global ignore rules for synced folders |
 | `device_uid` | string | none | Computers → Continue This Backup Here… | The computer this machine continues. Unset means "match by hostname" |
 | `conflict_sweep` | `off` / `report` / `enforce` | `report` | — | See [`conflict_sweep`](#conflict_sweep) |
+| `local_first` | bool | `true` | — | See [`local_first`](#local_first) |
 | `language` | gettext code | system | General → Appearance | Language of the app, tray and prompt, such as `de` or `pt_BR` |
 | `proton_theme` | bool | follow system | General → Appearance | Proton's colours instead of the system theme |
 | `online_map` | bool | `false` | General → Appearance | Street map for Places from OpenFreeMap |
@@ -116,6 +117,15 @@ were copied from.

 `PDFS_CONFLICT_SWEEP` overrides the setting for one run of the service.

+### `local_first`
+
+A new folder, a new file, a rename or a delete made through the mount is recorded locally and the
+call returns at once. The change goes to Drive from the queue, the same way it does offline, and
+`pdfs status` counts it until it lands.
+
+Set it to `false` to have these calls wait for Drive again, as before 3.0.0. The switch is there
+for one release, in case the queued path misbehaves for you; please report it if it does.
+
 ### `open_with`

 Decides how files picked in the search launcher or the app are opened. Rules are tried in order;
@@ -180,13 +190,16 @@ Command-line flags win over the file: `--gtk`, `--dmenu`, `--fzf` and `--menu`.
 | `PDFS_LOCALEDIR` | app, tray, prompt | Load translations from another directory (development) |
 | `PDFS_STAND_IN_WIDGETS` | app | `1` uses the libadwaita 1.5 fallback widgets on newer systems (development) |

-The acceptance suite has its own `PDFS_ACCEPTANCE_*` variables, listed in [TESTING.md](TESTING.md).
+The tests have their own variables (`PDFS_ACCEPTANCE_*`, `PDFS_SIM_*`, `PDFS_MIGRATE_DB`),
+listed in [TESTING.md](TESTING.md).

 ## The systemd service

-`proton-drive.service` is a user unit. It restarts the service whenever it exits, restarts it when
-it stops answering for two minutes (`WatchdogSec=120`), and caps its memory at 6 GiB. To change
-the unit without editing the packaged file, use a drop-in:
+`proton-drive.service` is a user unit started with your graphical session
+(`WantedBy=graphical-session.target`). It restarts the service whenever it exits, restarts it
+when it stops answering for two minutes (`WatchdogSec=120`), throttles it above 2 GiB of memory
+(`MemoryHigh`) and stops it at 6 GiB (`MemoryMax`). To change the unit without editing the
+packaged file, use a drop-in:

 ```bash
 systemctl --user edit proton-drive.service
@@ -31,12 +31,12 @@ time when the installed library has them (`crates/pdfs-gui/src/compat.rs`).
 | Path | Contents |
 |---|---|
 | `crates/pdfs-core` | Shared library: authentication and keyring (`auth`), configuration (`config`), SQLite schema and queries (`db/`), content cache (`cache`), control protocol (`control`), search scoring, sync ignore rules, Google Takeout parsing, machine profile |
-| `crates/pdfs-fuse` | The daemon: FUSE filesystem, read path (`reads`), write queue (`queue`, `drain`, `upload`), sync engine (`sync/`), remote events (`background`), push events for front ends (`events`), control handlers (`control`), photos, devices, supervisor |
+| `crates/pdfs-fuse` | The daemon: FUSE handlers (`filesystem`), the tree (`state`), reads (`reads`), the queue and the drain (`queue`, `drain`, `upload`), link state (`link`), the sync engine (`sync`, `sync/`), moves between locations (`relocate`), remote events (`background`), push events (`events`), control handlers (`control`), photos, devices, the supervisor, and the simulation tests (`sim/`) |
 | `crates/pdfs-cli` | The `pdfs` binary |
 | `crates/pdfs-gui` | `pdfs-app`, `pdfs-tray` and `pdfs-prompt`. Pages in `src/app/pages/`, shared widgets in `src/app/widgets/`, CSS and icons in `resources/` |
 | `po/` | Translation template, catalogs and the scripts that maintain them |
 | `packaging/` | systemd unit, desktop files, icon, PKGBUILD, RPM spec, AUR recipes |
-| `scripts/` | FUSE acceptance suite, map-data generators |
+| `scripts/` | FUSE acceptance suite, map-data generators, the wiki publisher |
 | `docs/` | This documentation |

 The GUI talks to the daemon only through the control socket. Anything a front end needs that the
@@ -87,8 +87,9 @@ cargo test --workspace --locked
 scripts/fuse-acceptance.sh --offline-only
 ```

-For changes to the FUSE layer, the write queue or the sync engine, also run the live acceptance
-cases described in [TESTING.md](TESTING.md).
+For changes to the FUSE layer, the queue or the sync engine, also run the
+[simulation runs](TESTING.md#simulation-runs), which CI runs only after a push to `main`, and the
+[acceptance suite](TESTING.md#acceptance-suite) on a test account.

 For changes to GUI strings, check that every catalog is complete:

@@ -136,6 +137,15 @@ file to `po/POTFILES.in`, run `po/update.sh`, and translate the new entries in e
 `#[serde(default)]`, so older files still load, and document it in
 [CONFIGURATION.md](CONFIGURATION.md).

+**A bug fix.** Add or update the entry in [BUGS.md](BUGS.md#adding-an-entry), cover the fix with a
+unit test, a simulation scenario or a `regression B<n>` acceptance case, and cite the entry in the
+code as `docs/BUGS.md B<n>`. Do not cite planning notes that are not in the repository.
+
+**A user-visible change.** Update the matching page (user guide, CLI reference, configuration)
+and the `[Unreleased]` section of [CHANGELOG.md](CHANGELOG.md). `scripts/publish-wiki.sh` copies
+the six user pages (`INSTALL`, `USER_GUIDE`, `CLI`, `CONFIGURATION`, `TROUBLESHOOTING`, `RECOVERY`)
+to the GitHub wiki, so keep their file names.
+
 ## Releasing

 Releases are cut from `main` by pushing a `v*` tag. `.github/workflows/release.yml` then:
@@ -160,5 +170,5 @@ git tag vX.Y.Z
 git push origin main vX.Y.Z
 ```

-Before a release that touches the filesystem or sync, run the managed live mode matrix from
-[TESTING.md](TESTING.md). Open release-assurance items are listed in [ROADMAP.md](ROADMAP.md).
+Before a release, work through [Before a release](TESTING.md#before-a-release). Open
+release-assurance items are listed in [ROADMAP.md](ROADMAP.md#release-assurance).
@@ -215,6 +215,14 @@ starts; to switch at once:
 systemctl --user restart proton-drive.service
 ```

+Coming from 2.8.0 or older, re-enable the service once. Those releases hooked it into
+`default.target`, which starts it before the desktop session is ready; on KDE that crashes
+`ksecretd` at every login. Signing in again or toggling "Start on login" does this as well:
+
+```bash
+systemctl --user reenable proton-drive.service
+```
+
 Database migrations run automatically and only move forward. A database written by a newer
 release refuses to open in an older one, so downgrading means clearing the local database (see
 [Troubleshooting](TROUBLESHOOTING.md#start-over-with-a-clean-local-state)).
@@ -5,7 +5,7 @@
 | Page | What it covers |
 |---|---|
 | [Installation](INSTALL.md) | Packages, building from source, first sign-in, updating and uninstalling |
-| [User guide](USER_GUIDE.md) | My files, available offline, synced folders, conflicts, Photos, sharing, Trash and versions, Computers, the search launcher, the tray |
+| [User guide](USER_GUIDE.md) | My files, available offline, synced folders, sync issues and conflicts, Photos, sharing, Trash and versions, Computers, the search launcher, the tray |
 | [Command-line reference](CLI.md) | Every `pdfs` command, grouped by task, and scripting with `--json` |
 | [Configuration](CONFIGURATION.md) | `config.json`, environment variables, file locations, the systemd service |
 | [Troubleshooting](TROUBLESHOOTING.md) | Diagnosing problems, common symptoms, starting over, reporting a bug |
@@ -16,13 +16,12 @@

 | Page | What it covers |
 |---|---|
-| [Development guide](DEVELOPMENT.md) | Building, running and debugging from source; releasing |
-| [Architecture](ARCHITECTURE.md) | Crates, read and write paths, sync engine, control protocol, threads, threat model |
-| [Testing](TESTING.md) | Unit tests and the FUSE acceptance suite |
+| [Development guide](DEVELOPMENT.md) | Building, running and debugging from source; common changes; releasing |
+| [Architecture](ARCHITECTURE.md) | Crates, the local tree, read and write paths, the queue, the sync engine, the control protocol, threads, threat model |
+| [Testing](TESTING.md) | Unit tests, simulation runs and the FUSE acceptance suite |
 | [Translating](TRANSLATING.md) | Adding and updating translations |
 | [Roadmap](ROADMAP.md) | Planned work and verification still owed |
 | [Bug ledger](BUGS.md) | Every tracked defect with its analysis and status |
-| [UI/UX plan](UI_UX_PLAN.md) | Design audit and notes behind the 2.x desktop app |

 Also see [CONTRIBUTING.md](../CONTRIBUTING.md) and [SECURITY.md](../SECURITY.md) in the repository
 root.
@@ -1,24 +1,54 @@
 # Roadmap

-Planned work and open verification, as of 2.5.0. Individual defects and their status live in
-[BUGS.md](BUGS.md), which is the authoritative ledger; this page groups what is left by theme.
-Nothing here is a promise of a date.
+Planned work and open verification after 3.0.0. Individual defects and their status are in
+[BUGS.md](BUGS.md); this page groups what is left by theme. Nothing here has a date.

+- [Sync engine](#sync-engine)
 - [Data safety and recovery](#data-safety-and-recovery)
 - [Features](#features)
 - [Performance and correctness](#performance-and-correctness)
 - [Verification still owed](#verification-still-owed)
 - [Release assurance](#release-assurance)

+## Sync engine
+
+3.0.0 records changes made through the mount locally and sends them from the queue
+([ARCHITECTURE.md §4](ARCHITECTURE.md#4-write-path)). What comes next:
+
+| Item | State | Notes |
+|---|---|---|
+| Remove the online path | Not started | The old way of sending a change inside the syscall, and the `local_first` switch that brings it back, go in the next release |
+| One applier for remote changes | Not started | Everything that comes from Drive (events, listings) changes the tree in one place, which is also the only place that tells the kernel. Replaces today's invalidation helpers and in-memory overlays |
+| Synced folders on the queue | Not started | Mirrored folders feed the local tree and use the same queue as the mount; `sync_entry` becomes the record of the last agreed state. Switching a folder's mode then moves no data except to evict or fetch content |
+| Batch trashes and moves | Deferred | See below |
+| Provisional values as types | Not started | A size or block geometry that is not known yet as its own type, so it cannot reach the kernel as if it were known |
+| Deadlines on every remote call | Partly done | The drain's calls and calls a syscall waits on have one; background calls outside the drain do not yet |
+
+**Batching trashes and moves.** `trash_nodes` and `move_nodes_streaming` take many nodes per call,
+but the queue sends one node per call. It was left out of 3.0.0 on purpose:
+
+- The 3.0.0 speed target is met without it. Making 1,000 files in 100 folders through the mount
+  takes 5.2 s on a LAN profile and 5.0 s on a Wi-Fi profile in the simulation
+  (`PDFS_SIM_MEASURE`, see [TESTING.md](TESTING.md#simulation-runs)).
+- The drain spends its time on creates. Each waits for Drive to list the new node before it
+  counts as landed, and batching does not shorten that.
+- One call answering for many ops has to be split back into results per op. Races in exactly that
+  step were the largest class of bugs found for 3.0.0 (B15x to B17x in [BUGS.md](BUGS.md)).
+
+Before building it, measure `rm -r` of a folder with 1,000 files on Wi-Fi. If that is slow, the
+cheaper fix is to drop the queued trashes of a trashed folder's contents: trashing the folder takes
+them along.
+
 ## Data safety and recovery

 | Item | State | Notes |
 |---|---|---|
-| Protect queued changes at shutdown | Not started | A systemd inhibitor lock while `staging/` holds unsent data, a warning when signing out, and a blocking `pdfs sync flush`. Today the queue is visible through `pdfs sync queue`, the tray and **Sync → Overview**, but nothing stops a shutdown (B66) |
-| Restore pins from the machine profile | Not started | `profile.json` records pins; `sync restore` does not apply them yet |
-| Profile backup health | Not started | A failed profile upload is a `WARN` in the log and nothing in the UI (B68) |
-| Rotated credentials survive a keyring failure | Open | Surface and retry keyring write failures so a rotated single-use refresh token is not lost (B61) |
-| Encrypt local state at rest | Not started | SQLCipher for `cache.db` and an AEAD for the content cache, keyed from the keyring. `sdk_cache.db` is already encrypted. See [ARCHITECTURE.md §8](ARCHITECTURE.md#8-threat-model-what-this-client-writes-to-disk-in-plaintext) |
+| Protect queued changes at shutdown | Not started | A systemd inhibitor lock while `staging/` holds unsent data, a warning when signing out, and a `pdfs sync flush` that waits for the queue. Today the queue is visible in `pdfs sync queue`, the tray and **Sync → Overview**, but nothing stops a shutdown (B66) |
+| Restore pins from the machine profile | Not started | `profile.json` records pins; `pdfs sync restore` does not apply them yet |
+| Profile backup health | Not started | A failed profile upload is a `WARN` in the log and nothing in the app (B68) |
+| Rotated credentials survive a keyring failure | Open | Report and retry keyring write failures, so a rotated single-use refresh token is not lost (B61) |
+| Restore never picks a new device silently | Open | Ask when the machine's device is ambiguous after a loss of local state (B67) |
+| Encrypt local state at rest | Not started | SQLCipher for `cache.db` and an AEAD for the content cache, keyed from the keyring. `sdk_cache.db` is already encrypted. See [ARCHITECTURE.md §10](ARCHITECTURE.md#10-threat-model-what-this-client-writes-to-disk-in-plaintext) |

 ## Features

@@ -26,9 +56,10 @@ Nothing here is a promise of a date.
 |---|---|---|
 | File-manager integration | Not started | Context-menu actions (available offline, share link, versions) and sync badges for Nautilus, Dolphin and Thunar |
 | Terminal UI | Not started | `pdfs tui` with transfers, sync state and logs |
-| Multiple accounts | Not started | Separate config, state and mountpoint per profile, one daemon each |
+| Multiple accounts | Not started | Separate config, state and mountpoint per account, one daemon each |
 | Mount options | Not started | Read-only mount, `allow_other` |
-| Symbolic links | Not started | Proton Drive has no link type; links would need a placeholder format. Until then, creating one fails with `EOPNOTSUPP` |
+| Symbolic links | Not started | Proton Drive has no link type; links would need a placeholder format. Until then, `symlink` fails with `EPERM` |
+| `fsync` that waits for Drive | Idea | `fsync` means "durable locally". A mount option or an xattr could offer "on Drive" without slowing the default |
 | Add someone else's photo to your album | Blocked | Needs `copyPhoto` in the SDK |
 | Photo name search | Not started | Photos search by date and filters only |
 | Automatic photo upload from a folder | Not started | |
@@ -39,34 +70,38 @@ Nothing here is a promise of a date.

 | Item | Notes |
 |---|---|
-| Saturating stream-ring accounting | `self.bytes -= …` in `crates/pdfs-fuse/src/reads.rs` should saturate so an accounting drift cannot wrap in release builds |
+| Saturating stream-ring accounting | `self.bytes -= …` in `crates/pdfs-fuse/src/reads.rs` should saturate, so an accounting drift cannot wrap in release builds |
 | Block geometry learned one read late | The first read of a file plans on 4 MiB blocks; accepted as a bounded cost (B87) |
-| Path-based commands under secondary mounts | `pin`, `rename`, `move`, `rm` and sharing cannot name a path inside an on-demand synced folder yet (B88) |
-| Unicode normalization | NFC and NFD names are distinct, deliberately (B36) |
-| Pipelined node enumeration | Faster cold listings of large folders |
+| Path-based commands under online-only folders | `pin`, `unpin`, opening a file, uploads, sharing and versions cannot name a path inside an online-only synced folder yet. `rm`, `rename`, `mkdir` and `move` can (B88) |
+| Unicode normalization | NFC and NFD names are distinct, on purpose (B36) |
+| Pipelined node enumeration | Faster first listings of large folders |

 ## Verification still owed

-Fixes marked *unverified* in [BUGS.md](BUGS.md) have unit or offline coverage but have not been
-driven against a live account. The larger outstanding runs:
+Fixes marked *unverified* in [BUGS.md](BUGS.md) have unit or simulation coverage but have not
+been driven against a live account. The larger runs still owed:

+- **A clean account run on 3.0.0.** The last account run before the release (2026-10-04, on Wi-Fi)
+  failed only its cleanup, on a script bug fixed since. No full run with `--journal-check` has
+  passed on the released code yet.
 - **Disaster-recovery drill.** Register a device, sync a folder, delete all local state, restore
-  with `pdfs sync restore` and compare the tree byte for byte. See [RECOVERY.md](RECOVERY.md).
- **Second-account sharing.** Shared trees on a foreign volume, accepting invitations, changing
+  with `pdfs sync restore`, and compare the tree byte for byte. See [RECOVERY.md](RECOVERY.md).
+- **Second-account sharing.** Shared folders on a foreign volume, accepting invitations, changing
  roles, the viewer cases of `regression B34`, and an editor writing into someone else's share.
- **Fault injection.** Network loss mid-upload, a full disk during staging, and crash points
-  across the write publication path (after each fsync, rename and queue commit).
+- **Fault injection on a real account.** Network loss mid-upload, a full disk during staging, and
+  crashes at each step of publishing a write. The simulation covers link loss and restarts against
+  the fake Drive, not a kill at an arbitrary point.
+- **Acceptance runs across a network drop.** A case that spans an outage times out while the queue
+  replays, instead of being reported as interrupted.
 - **CAPTCHA sign-in** against a real verification request (B8).
- **Managed live mode matrix** before each release:
-  `scripts/fuse-acceptance.sh --managed-live <empty-a> <empty-b>`. See [TESTING.md](TESTING.md).
- **The overnight hang** (B91) is not diagnosed yet. The supervisor and `pdfs diagnostics` exist to
-  catch the next occurrence.
+- **The overnight hang** (B91) is not diagnosed. The supervisor and `pdfs diagnostics` exist to
+  catch the next one.

 ## Release assurance

 | Item | State |
 |---|---|
-| Tag, workspace and PKGBUILD version agreement | Enforced by the release workflow |
+| Tag, workspace and PKGBUILD version agree | Enforced by the release workflow |
 | Clean-install test of the `.deb` and `.rpm` in a VM | Pending (B62) |
 | Protocol version identity between front ends and daemon | Open (B63) |
 | SBOM, provenance and checksums for release artifacts | Open (B65). The RPM is GPG-signed |
@@ -1,209 +1,265 @@
 # Testing

-The normal Rust suite exercises the metadata database, sync planner, offline
-queue, write staging, cache, and FUSE handler state without requiring a Proton
-account:
+Three layers check the client, from fast and offline to slow and against a real account:

-```console
+| Layer | Needs | Runs in CI |
+|---|---|---|
+| [Unit tests](#unit-tests) | Nothing | Every push and pull request |
+| [Simulation runs](#simulation-runs) | `/dev/fuse` | Every push to `main` |
+| [Acceptance suite](#acceptance-suite) | Nothing for the reference run; a signed-in account for the rest | The reference run only |
+
+## Unit tests
+
+```bash
 cargo test --workspace
 cargo clippy --workspace --all-targets -- -D warnings
 ```

-## Filesystem API and live FUSE acceptance suite
+Tests sit in `#[cfg(test)]` modules next to the code. Database tests are in
+`crates/pdfs-core/src/db/tests.rs`; a schema change adds one that migrates from the previous
+version.

-The account-free suite exercises the filesystem syscall contract against a
-temporary local directory. This validates the runner and covers creation/open
-flags, positioned and vectored I/O, truncation and sparse files, `mmap`,
-`sendfile`, `copy_file_range`, durability barriers, namespace/error semantics,
-`renameat2` flags, open-file lifetime, names and enumeration, readdir stability
-under concurrent mutation, metadata updates, extended attributes, allocation and
-punched holes, refusal semantics for unimplemented operations, concurrent I/O,
-and real application workloads. It never reads application state or contacts
-Proton:
+To check the migrations against a real database, point `PDFS_MIGRATE_DB` at it and run the
+ignored test. It migrates a copy taken with `VACUUM INTO` and never writes the database named:

-```console
-scripts/fuse-acceptance.sh --offline-only
+```bash
+PDFS_MIGRATE_DB=~/.local/state/proton-drive-linux/cache.db \
+  cargo test -p pdfs-core a_copy_of_a_real_database -- --ignored
 ```

-Kernel/FUSE behavior and remote convergence need a real mount. Live testing is
-explicitly opt-in and always runs the account-free contract first. It runs
-destructive POSIX operations only below a fresh `pdfs-acceptance-*` directory.
-It refuses paths that are not FUSE mounts and removes its directory on success,
-failure, or interruption.
+## Simulation runs

-Use a dedicated test account without irreplaceable data:
+The simulation runs (`crates/pdfs-fuse/src/sim/`) start real daemons with real FUSE mounts against
+an in-memory Drive, `FakeDrive`. The daemon runs as in production (drain workers, sync engine,
+event feed, online probe, control socket); only its Drive is fake. `FakeDrive` has the faults the
+real one has: listings that lag a create, renames refused for a stale name hash, no atomic
+replace, delayed and reordered events, requests that stall or lose their answer, per-request
+latency, and blocks of uneven size.

-```console
-scripts/fuse-acceptance.sh --live /mnt/on-demand-testmount
+A run draws a sequence of steps from a seed: syscalls through a client's mount, the link going
+down and up, restarts, settles (every queue must drain within a budget), and files deleted while
+the drain holds a write to them. Every syscall is checked against an in-memory model of the
+filesystem as it happens. At the end every link comes up and the run checks:
+
+1. **No loss and POSIX.** Drive's copy of each client's folder is what its model says.
+2. **No false conflicts.** No conflict copy anywhere; each file has one writer.
+3. **Convergence.** Each mount shows Drive's tree.
+4. **Liveness.** No syscall took longer than its budget, and every queue drained once the links
+   were up. A call that never returns is caught by a watchdog that writes every thread's stack to
+   `stacks.txt` in the run's state directory.
+
+| Test | Seeds |
+|---|---|
+| `one_client_on_a_good_link` | 12 |
+| `one_client_deleting_files_as_they_upload` | 3 |
+| `one_client_with_stale_hashes_and_reordered_echoes` | 6 |
+| `one_client_on_a_flaky_link` | 4 |
+| `one_client_on_a_slow_link` | 4 |
+| `three_clients_one_writer_each` | 3 |
+
+`sim/daemon.rs` holds scenario tests for single bugs, run the same way.
+
+The tests mount FUSE, so they are ignored by default:
+
+```bash
+cargo test -p pdfs-fuse --lib sim:: -- --ignored --test-threads=1   # what CI runs
+PDFS_SIM_SEEDS=50 cargo test -p pdfs-fuse --lib sim::run -- --ignored --test-threads=1
+PDFS_SIM_SEED=7 RUST_LOG=pdfs_fuse=debug cargo test -p pdfs-fuse --lib \
+  sim::run::tests::one_client_on_a_flaky_link -- --ignored --exact --nocapture
 ```

-### The mount is diffed against an ordinary filesystem
+| Variable | Effect |
+|---|---|
+| `PDFS_SIM_SEEDS` | How many seeds each test runs, from 1 |
+| `PDFS_SIM_SEED` | Replay one seed. A failing run prints the seed, the last steps, and where it kept its state |
+| `PDFS_SIM_MEASURE` | Run `a_thousand_files_drain_as_fast_on_wifi_as_on_lan`, which times 1,000 files in 100 folders on a LAN and a Wi-Fi profile and prints the times |

-The local reference run is not only a self-test of the runner. Every case
-records the facts it established, and a live run is compared against those
-recordings, so a case fails when the mount *differs* from an ordinary
-filesystem — not only when it raises. The report names the exact key:
+A failure is a seed that can be replayed, but the daemon uses real threads, so a race may need
+several replays. In CI, the `simulation` job uploads the stacks of a hung run as an artifact.

-```
-  [DIVERGENCE] live FUSE /mnt/testmount does not match the reference filesystem:
-    ! creation and open flags.truncated.size: live=6 reference=0
+## Acceptance suite
+
+`scripts/fuse-acceptance.sh` checks the filesystem contract a program sees: creation and open
+flags, positioned and vectored I/O, truncation and sparse files, `mmap`, `sendfile`,
+`copy_file_range`, durability barriers, renames and their `renameat2` flags, open-file lifetime,
+names, `readdir` under concurrent change, metadata, extended attributes, holes, refusals of
+unsupported operations, concurrent I/O, and real application workloads.
+
+> [!CAUTION]
+> Every mode except `--offline-only` creates and deletes real files in Proton Drive. Use a test
+> account with nothing you cannot lose.
+
+### Modes
+
+```bash
+scripts/fuse-acceptance.sh --offline-only            # the reference run; no account
+scripts/fuse-acceptance.sh                           # the signed-in account, every mode pairing
+scripts/fuse-acceptance.sh --quick                   # one on-demand/mirror pairing instead of four
+scripts/fuse-acceptance.sh --live /mnt/testmount     # mounts you set up yourself
+scripts/fuse-acceptance.sh --managed-live /mnt/a /mnt/b
 ```

-Facts are recorded in one of two ways, chosen in the test body:
+**The reference run** always runs first, against a temporary local directory. It records the
+facts each case establishes, and every mount is then **compared** against those facts. A case
+fails when the mount differs from an ordinary filesystem, not only when it raises. A fact that may
+legitimately differ (inode numbers, block counts, which optional syscalls exist) is **noted**
+instead, and listed under the target's `accepted` line. The choice is made in the test body, so
+the accepted differences are visible where they are accepted. Prefer `record`; use `note` only
+for something a network filesystem cannot do.

- **compared** — a claim about filesystem semantics. The mount must agree.
- **noted** — context that legitimately differs: inode numbers, block counts,
-  reported mode bits, and which optional syscalls exist at all. Reported under
-  `[capabilities]`, never a failure.
+**An account run** (no mode):

-Because the choice is made at each call site, the set of accepted divergences
-is visible in the test that accepts it. There is no separate allowlist to drift
-out of date. When adding a case, prefer `record`; reach for `note` only when an
-ordinary filesystem can do something a network filesystem genuinely cannot.
+1. Runs the reference.
+2. Runs the contract in a new `pdfs-acceptance-<id>` folder in My files, and at the end reads back
+   a file the run wrote.
+3. Registers two sync folders under `~/.cache/pdfs-acceptance/run-<id>/` and runs the contract and
+   the move cases in every pairing of on-demand and mirror. Before a folder switches to on-demand,
+   a new file is written into it; once mounted, the file must be listed with its bytes. In every
+   pairing each folder must still hold the file written into it at setup.
+4. Removes everything it made, locally and on Drive, and reports `cleanup`. A run that leaves
+   anything behind fails.

-### Operations the filesystem does not implement
+Cleanup finds remote folders by uid, never by name, so nothing of yours is touched. It removes
+each sync folder with `sync rm --delete-remote`, trashes the My files folder, deletes both from
+the trash for good, and checks that a fresh trash listing no longer shows them. Queued ops that
+still name one of its folders count as left behind. Cleanup also runs on a failure, Ctrl-C,
+`SIGTERM` or `SIGHUP`; while it runs, two more interrupts are ignored and a third abandons it.

-`git`, `rsync`, `cp -a`, `tar`, `df` and most installers probe for symlinks,
-hard links, FIFOs, device nodes, `statfs`, file locks, `copy_file_range`,
-`O_DIRECT` and `SEEK_HOLE` whether or not a filesystem offers them. The suite
-asserts that each either works or is *refused cleanly* — a recognised errno,
-never `EIO` and never a hang. A refusal that is merely unimplemented is fine;
-one that is dirty breaks software that never asked for the feature.
+Each run writes what it is about to create to `~/.cache/pdfs-acceptance/run-<id>/manifest.json`
+first and holds a lock on that directory. A later run finishes the cleanup of a run that died, and
+removes stray `pdfs-acceptance-<32 hex>` folders no live run claims: in My files (older than
+`PDFS_ACCEPTANCE_REAP_AGE`, default one hour), under the acceptance home, and in the trash. It
+does not start while anything is left.

-### Regressions from the bug ledger
+Ops that were queued before the run started are not the run's: it prints one `NOTE` line naming
+them, and its queue waits ignore them.

-Cases named `regression B<n>` reproduce a bug from `docs/BUGS.md` so it stays
-fixed. B69 (identical rewrite must not fork a `(sync-conflict …)` copy), B70 (an
-in-flight `.crdownload` must not be sealed as a revision) and B74 (a file
-renamed after close must keep its content) need a real mount and a reachable
-daemon; they are skipped, not failed, without one.
+**`--live PATH...`** runs the contract on mounts you set up, and leaves the sync configuration
+alone. It works only below a new `pdfs-acceptance-*` directory, refuses paths that are not FUSE
+mounts, and removes its directory afterwards. The first path must be a FUSE mount; later paths may
+be another mount or a mirrored folder. If all paths show the **same remote folder**, set
+`PDFS_ACCEPTANCE_CONVERGENCE=1` to also check that bytes written through the first appear through
+the others.

-B74 was found by exactly this mechanism: the B70 case failed, and narrowing it
-produced a smaller reproduction that got its own case. The defect is fixed and
-live-validated (2026-07-26); the case now guards against its return.
+**`--managed-live A B`** takes two existing, empty, unmounted directories, registers them as sync
+folders, and runs every pairing as an account run does, then deletes the remote folders. It
+refuses non-empty paths, mounts, and paths already in `pdfs sync list`.

-**B79** (an on-demand device folder accepts writes) discovers its target from
-`pdfs locations --json` and skips when this machine has no mounted on-demand
-folder. It is the cheap standing guard against a *cross-mount* permission
-regression: the primary mount holds device-folder nodes too, and the queue guard
-intersects what every live inode space says about a uid, so a fail-closed
-classification in one mount denies writes in another.
+### Reading the output

-**B34** (a viewer-role share is read-only) and **B34b** (an editor-role share
-still writes) locate their subject through `pdfs shared-with-me --json`, which
-now carries `role` and a mount-relative `path`. Both skip when the account has no
-accepted share at that role — B34 needs a **second account** to have shared a
-folder read-only, which is the one part of the sharing suite that cannot be
-self-served. B34b degrades gracefully in the other direction: a shared *file*
-gets its mode bits and `W_OK` checked but is never written to, because it is
-someone else's document.
+A run opens with the mode, the `pdfs` binary and version, Python, the kernel, the per-case limit
+and the options. Each target then names its root, the storage behind it, the daemon and the
+number of cases, followed by one line per case:

-B34's fourth assertion is the load-bearing one: `pending_uploads` and
-`pending_changes` must be **unchanged** across the refused writes. Mode bits
-alone would pass a fix that still admitted the write into `pending_op`, which is
-the actual harm — a background drain failing 403 forever.
-
-**Synthetic `Shared with me/` directory contract** asserts the virtual directory
-enumerates, reports `0555`, and refuses `mkdir`/`rmdir`/`rename`. It skips when
-the directory is absent (an account with no accepted shares).
-
-A regression case asserts against the *remote* outcome, so it must wait for the
-queue to drain before reading. Reading straight back through the mount proves
-nothing: the local attribute and content caches will happily return the bytes
-that were just written even when nothing reached Drive, which is precisely how
-B74 stayed invisible.
-
-### Timeouts, reports, and hung mounts
-
-A wedged FUSE operation cannot be interrupted from Python, so each case runs
-under a soft alarm (`--timeout`, default 180s) that reports the case and lets
-cleanup run, backed by a hard stop that dumps every thread's stack and exits.
-That backstop is the only way to learn *where* a mount hung. A timeout ends the
-run: later cases against a wedged mount produce noise, not information.
-
-```console
-scripts/fuse-acceptance.sh --live /mnt/testmount \
-  --timeout 300 --report-junit results.xml --budget 30
+```
+==> live FUSE /mnt/testmount
+  -> root      /mnt/testmount/pdfs-acceptance-…
+  -> storage   FUSE mount /mnt/testmount (fuse.protondrive)
+  -> daemon    pdfs 3.0.0, user@proton.me, online, 0 queued ops
+  -> cases     45 of 45
+  [ 1/45] creation and open flags .................................. ok       0.41s
+  …
+  [21/45] throughput floors ........................................ ok      48.20s
+          write 31 MiB/s, read 54 MiB/s, 4 KiB writes 12.0 MiB/s, metadata 9 ops/s
+  …
+  -> reference matches the ordinary filesystem in 412 compared observations
+  -> result    44 passed, 1 skipped in 11m02s
 ```

-`--report-json` also writes every recorded observation, which is what to attach
-to a bug report. `--budget SECONDS` flags cases that pass but got slower —
-B5 was a 186 ms-per-call regression that a pass/fail suite could not see.
-`--list` prints every case and which targets it runs against, and `--fail-fast`
-stops at the first failure.
+A case ends as `ok`, `FAIL`, `TIMEOUT`, `skip` (it does not apply to the target), or `known` (an
+`open B<n>` case reproduced a bug that is still open). Dimmed lines under a case hold its details.
+A failed `regression B<n>` case points to its entry in [BUGS.md](BUGS.md).

-`--journal-check` fails the run if `proton-drive.service` logged any error while
-it ran. A suite can pass every assertion while the daemon logs failures behind
-it; that has happened, and it was caught only by reading the journal by hand.
+The run ends with a table of every target, the report paths, the slowest cases, cases over
+`--budget`, known issues that still reproduce, errors the daemon logged, and each failure. The
+last line is `PASS:` or `FAIL:` with the totals. Colour is used only on a terminal and never with
+`NO_COLOR` set.

-Abandoned `pdfs-acceptance-*` roots from a crashed run are removed at startup,
-but only if they match the exact generated name and are over an hour old
-(`PDFS_ACCEPTANCE_REAP_AGE`), so a concurrent run is never disturbed.
+### What the cases cover

-### Automated mode matrix
+Besides the syscall contract:

-The managed live runner accepts two existing, empty, unmounted directories. It
-registers both as new sync folders, waits for initial synchronization, then
-tests all four pairs in order: on-demand/on-demand, on-demand/mirror,
-mirror/on-demand, and mirror/mirror. Every transition must become idle, and an
-on-demand folder must actually appear as a mount before its contract runs.
+- **Block boundaries.** Files from 0 bytes to two 4 MiB blocks plus 3 bytes, every size next to a
+  boundary, and overwrites that grow, shrink and reshape them.
+- **Unusual names.** 255 bytes, NFC and NFD forms of the same text, newline, tab, emoji,
+  characters Windows forbids, leading and trailing spaces, a case-only rename.
+- **A deep tree and a wide folder.** 24 levels renamed at the top; 128 entries created
+  concurrently, unlinked concurrently, then `rm -rf`.
+- **Rename patterns.** Swaps, chains, log rotation, replacing a file under an open reader, the
+  `EISDIR`, `ENOTDIR` and `ENOENT` refusals.
+- **Handle coherency.** Unsaved writes seen by a second handle, two `O_APPEND` writers, 30 rewrite
+  generations, a truncate under a reader.
+- **Throughput.** 64 MiB written and read, 1 MiB in 4 KiB writes, metadata on 100 files. The case
+  fails below `PDFS_ACCEPTANCE_MIN_MIBPS` (default 10) or `PDFS_ACCEPTANCE_MIN_OPS` (default 20
+  operations per second, 3 on a FUSE mount). `0` turns a floor off.
+- **Operations the filesystem does not implement.** `git`, `rsync`, `cp -a`, `tar` and installers
+  probe for symlinks, hard links, FIFOs, device nodes, locks, `O_DIRECT` and `SEEK_HOLE`. Each must
+  work or be refused cleanly: a known errno, never `EIO`, never a hang.
+- **Moves between locations** (`managed` in `--list`). Trees moved between two sync folders in
+  both directions, several sources in one `pdfs move`, and a tree through My files and out again.
+  The refusals must move nothing and lose nothing: a name already taken, a folder into itself, a
+  mirrored source holding something Drive lacks, a file still open for writing.
+- **The CLI.** `pdfs` into a closed pipe exits 0 with nothing on stderr; `pdfs mkdir`, `rename`
+  and `rm` by local path, and their refusals.

-```console
-mkdir -p /mnt/pdfs-test-a /mnt/pdfs-test-b
-scripts/fuse-acceptance.sh --managed-live /mnt/pdfs-test-a /mnt/pdfs-test-b
-```
+### Regressions and open bugs

-This creates remote folders and permanently deletes those test remotes during
-cleanup. It refuses non-empty paths, existing mounts, and paths already present
-in `pdfs sync list`. Use `PDFS_ACCEPTANCE_SYNC_TIMEOUT` to extend transition
-timeouts and `PDFS_ACCEPTANCE_PDFS` to select a non-installed CLI binary, for
-example `target/debug/pdfs`.
+A case named `regression B<n>` reproduces an entry of [BUGS.md](BUGS.md) so it stays fixed. Most
+need a live mount and a reachable daemon, and are skipped without one. `--list` prints every case
+and the targets it runs on.

-### Durability drill
+A regression case checks the outcome **on Drive**, so it waits for the queue first. Reading back
+through the mount proves nothing: the local caches return the bytes just written whether or not
+they reached Drive. A write is queued when the kernel releases the file, after `close(2)` has
+returned, so a case that reads `pdfs sync queue` right after writing waits for the ops it expects.

-`--durability` restarts `proton-drive.service` in the middle of the suite and
-re-verifies the bytes written before it. `staging/` and `recovery/` can hold the
-only copy of a file whose upload has not finished, so this is the case that
-proves the queue is persistent rather than in-memory. It is opt-in because it
-interrupts a running daemon; `PDFS_ACCEPTANCE_UNIT` selects a different unit.
+A case named `open B<n>` checks a bug that is still open. While it reproduces, the case ends as
+`known`: listed at the end, but not a failure. When it passes, the bug is fixed: rename the case to
+`regression B<n>` and make it fail with `check`. No case is open at the moment.
+
+Some cases need what a test account cannot provide alone and skip without it: B34 needs a folder
+shared read-only by a **second account**, B34b one shared with editor rights, and B79 an on-demand
+synced folder.
+
+### Timeouts, reports and hung mounts
+
+A hung FUSE call cannot be interrupted from Python. Each case runs under a soft alarm (`--timeout`,
+default 180 s, or `PDFS_ACCEPTANCE_TIMEOUT`) that reports the case and lets cleanup run, backed by
+a hard stop that dumps every thread's stack and exits. After a timeout the run checks whether the
+mount still answers a `stat` and a listing within 15 s. If it does, the target goes on; if not, its
+remaining cases are skipped. Cases that make many round trips by design get twice the limit.
+
+| Option | Effect |
+|---|---|
+| `--report-json PATH` | Every result and recorded observation. Attach it to a bug report |
+| `--report-junit PATH` | JUnit XML. `known` is reported as skipped |
+| `--budget SECONDS` | Flags cases that pass but take longer (`PDFS_ACCEPTANCE_BUDGET`) |
+| `--journal-check` | Fails the run if `proton-drive.service` logged an error during it, or the warnings "queued write conflicts; keeping a conflict copy" and "a fuse worker has held the same job for a long time" |
+| `--durability` | Restarts the service mid-suite and checks the bytes written before it. Proves the queue survives a restart. `PDFS_ACCEPTANCE_UNIT` names another unit |
+| `--fail-fast` | Stops at the first failure |
+| `--list` | Prints every case and its targets |

 ### Selecting cases

-During development, `PDFS_ACCEPTANCE_ONLY` runs tests whose descriptive name
-contains the supplied text (for example `PDFS_ACCEPTANCE_ONLY=namespace`). A
-release acceptance run must leave it unset so the complete contract executes.
+`PDFS_ACCEPTANCE_ONLY` runs the cases whose name contains the text, ignoring case. Separate several
+with commas (`PDFS_ACCEPTANCE_ONLY=B116,B117`). A filter that matches no case at all fails, as the
+typo it is. A release run leaves it unset.

-A filter naming a live-only case (every `regression B<n>` is one) selects nothing
-in the account-free reference run, which is not an error — that target simply has
-nothing to do. Only a filter matching *no case at all* fails, as the typo it is.
+| Variable | Effect |
+|---|---|
+| `PDFS_ACCEPTANCE_PDFS` | The `pdfs` binary to use, for example `target/debug/pdfs` |
+| `PDFS_ACCEPTANCE_SYNC_TIMEOUT` | Seconds a sync folder may take to settle after a change of mode |
+| `PDFS_ACCEPTANCE_REAP_AGE` | Age in seconds after which a stray `pdfs-acceptance-*` folder is removed (default 3600) |
+| `PDFS_ACCEPTANCE_CONVERGENCE` | `1` checks that several `--live` paths show the same bytes |
+| `PDFS_ACCEPTANCE_MIN_MIBPS`, `PDFS_ACCEPTANCE_MIN_OPS` | Throughput floors |
+| `PDFS_ACCEPTANCE_UNIT` | The systemd unit `--durability` restarts |

-Passing more paths runs the same filesystem suite independently against each.
-The first path must be the FUSE mount under test; later paths may be another
-FUSE mount or a normal local mirror filesystem:
+## Before a release

-```console
-PDFS_ACCEPTANCE_SYNC_TIMEOUT=180 \
-  scripts/fuse-acceptance.sh --live /mnt/on-demand-testmount /mnt/testmount
-```
+1. The quality gates and the simulation runs pass in CI.
+2. A full account run with `--journal-check` passes on a test account:
+   `scripts/fuse-acceptance.sh --journal-check`.
+3. Fixes marked *unverified* in [BUGS.md](BUGS.md) that a run now covers are marked verified.

-If two paths really are views of the **same remote folder**, enable an
-additional byte-for-byte convergence check explicitly:
-
-```console
-PDFS_ACCEPTANCE_CONVERGENCE=1 \
-  scripts/fuse-acceptance.sh --live /mnt/first-view /mnt/second-view
-```
-
-Do not enable that flag merely because two sync folders belong to the same
-account. Their configured remote UIDs must be identical.
-
-Normally the live suite applies the same API contract independently to each
-supplied mount. In convergence mode it exercises the primary once and verifies
-that the resulting bytes appear through every secondary view. A pass is
-strong evidence for those paths, not a blanket data-loss guarantee. Before a
-release, also run the recovery drills in `docs/RECOVERY.md` and inspect
-`docs/BUGS.md` for live-verification items.
-
-The runner accepts already-mounted paths instead of starting a daemon. This
-keeps authentication and keyring setup explicit and prevents it from silently
-reusing or replacing the normal application state directory.
+What no automated run covers yet is listed under
+[Verification still owed](ROADMAP.md#verification-still-owed).
@@ -113,22 +113,40 @@ pdfs refresh Documents
 **"Permission denied" when writing** — the item is in a share where you are a viewer, or under
 `Shared with me/`, which is read-only as a folder. Check your role with `pdfs shared-with-me`.

-**A program says "Operation not supported"** — Proton Drive cannot store symbolic links, hard
-links, device files or FIFOs. The error is intentional. Use a synced folder for
-projects that need them, or exclude those paths.
+**`ln` or another program fails with "Operation not permitted"** — Proton Drive cannot store
+symbolic links, hard links, device files or FIFOs, so creating one fails at once. The error is
+intentional. Use a synced folder for projects that need them, or exclude those paths.

 ## Uploads and sync

-**Something is stuck uploading** — list the queue and retry:
+**A change shows here but not on other devices** — changes are recorded on this computer first
+and sent from a queue. List what is still waiting, and what needs attention:

 ```bash
 pdfs sync queue
+pdfs sync issues
+```
+
+The app shows the same on **Sync → Overview**. A change waits while the service is offline or
+sync is paused (`pdfs status`), and backs off after a failure. To retry at once:
+
+```bash
 pdfs sync retry           # every failed operation
 pdfs sync retry 42        # one operation
 ```

-The app shows the same list on **Sync → Overview**. An operation that keeps failing shows its
-error there.
+A change Proton Drive refuses (storage full, access taken away, folder gone) is listed by
+`pdfs sync issues` with what to do. It stays queued until you fix the cause or drop it. Dropping
+it undoes it here; save a file's content first if you want to keep it:
+
+```bash
+pdfs sync export 42 ~/Desktop/
+pdfs sync discard 42
+```
+
+If you suspect the local-first behaviour of 3.0.0 itself, `"local_first": false` in `config.json`
+makes the Proton Drive folder wait for Proton Drive again while online (see
+[CONFIGURATION.md](CONFIGURATION.md#local_first)), and please report the problem.

 **A file in a synced folder does not upload** — check that:

@@ -1,354 +0,0 @@
-# UI/UX audit and improvement plan
-
-Audit date: 2026-09-23. Scope: `pdfs-gui` (all pages, dialogs, photo viewer), `pdfs-tray`, and the
-backend capabilities the UI would need. File references are to `crates/pdfs-gui/src/app/` unless
-stated otherwise.
-
-## 1. Summary
-
-The client is functionally rich but the UI is built page by page, and it shows:
-
- **No sync control surface.** There is no way to pause or resume sync, no list of what is stuck or
-  failing, and no conflict overview. The backend has no pause at all, no per-op listing, and no
-  per-file conflict record (conflicts exist only as `(sync-conflict <ts>)` files plus activity rows).
-  The GUI reads `online`, `pending_uploads` and `pending_changes` from `Status` and ignores
-  `failing_ops`, `failing_error`, `parked_uploads` and `staged_*`.
- **Information architecture is scattered.** Live transfers are a group on *Settings* while the
-  *Activity* page is history only. *Locations* and *Computers* point at each other. Import lives under
-  Settings but is launched from Gallery and returns to Settings. Sign-out, quota, mount status,
-  pinned files, import and developer info all share the Settings page.
- **Chrome is non-standard.** Every page draws its own title and toolbar row under an almost empty
-  `AdwHeaderBar` whose title is always "Proton Drive". Two stacked bars, wasted height, no current
-  folder in the title.
- **Icons and wording drift.** Upload uses `document-send-symbolic` (reads as "send"), offline uses
-  stars (reads as "favorite"), trash icons mean "stop syncing", "remove device" and "remove
-  bookmark". "Keep offline" / "Unpin" / "Remove offline copy" / "Available offline" are one concept.
-  "Computers" vs "device", "Gallery" vs "Photos", "mount service" vs "daemon" vs "Connect".
- **Theming is hardcoded.** `PROTON_PURPLE` overrides the system accent; badge, viewer and tile
-  colours are hex/rgba literals and ignore light, dark and high-contrast modes.
- **Several visible bugs** (section 9).
-
-## 2. Design principles
-
-1. **Follow GNOME HIG and current libadwaita.** The system has libadwaita 1.9; the crate is pinned to
-   feature `v1_5`. Raise it to at least `v1_7` to get `adw::Spinner`, `ToggleGroup`,
-   `InlineViewSwitcher`, `ButtonRow`, `WrapBox`, `BottomSheet`, and (1.8) `ShortcutsDialog`.
-2. **Sync state is first class.** The user must always see: up to date / syncing / paused / offline /
-   needs attention, and be one click from pausing or from the list of problems.
-3. **One term, one icon, one place** per concept (glossary in section 8).
-4. **Secondary and destructive actions go into menus.** Rows get at most one visible suffix action
-   plus a `view-more-symbolic` menu. Destructive actions are red inside the menu and in the confirm
-   dialog, not as filled buttons in headers.
-5. **Never block on the network visibly.** Keep old content on screen while reloading, show a header
-   spinner, never flash the whole page to a "Loading…" status page.
-6. **Respect the system.** Use the system accent by default (brand purple stays on login, app icon
-   and an opt-in toggle). Use named colours (`@success_color`, `@warning_color`, `@error_color`).
-
-## 3. New information architecture
-
-### Sidebar
-
-```
-Proton Drive                     (header: app name)
-  My files
-  Photos
-  Shared with me        (badge: pending invitations)
-  Shared by me
-  Computers
-  Trash
-─────────────
-  Sync                  (badge: issue count, icon reflects state)
-─────────────  footer
-  [●] Up to date · Pause          ← sync status strip, click opens Sync
-  ▓▓▓░░░ 269 GiB of 1.6 TiB       ← quota
-  (avatar) user@proton.me   ⋮     ← account menu: Preferences, Sign out…
-```
-
- **Remove** sidebar rows: *Locations* (merged into Sync), *Activity* (becomes the Sync "History"
-  view), *Settings* (becomes an `AdwPreferencesDialog`, `Ctrl+,`).
- **Rename** *Gallery* to *Photos* and *Shared* to *Shared by me*.
- Primary menu: Preferences, Keyboard Shortcuts, About. The About dialog's `debug_info` gets app
-  version, user agent, daemon status and config path (replacing the "Developer" group).
-
-### Sync page (new, replaces Locations + Activity + Settings→Activity)
-
-Top: an `AdwBanner`-style status card with state icon, one-line summary ("Syncing 12 files · 3.4
-MB/s", "Paused until you resume", "2 files need attention") and one primary button: **Pause** /
-**Resume** (split button with "Pause for 1 hour / until tomorrow / until resumed").
-
-Below, an `InlineViewSwitcher` with four views:
-
-1. **Issues** (default when non-empty): conflicts, failing uploads (`last_error`, attempts, next
-   retry), folders in `error`/`conflict` state, parked uploads older than N minutes. Each row has a
-   primary fix action (Resolve…, Retry now) and a menu (Show in folder, Discard change…).
-2. **Transfers**: in-flight uploads and downloads with progress, speed, cancel; background jobs
-   (thumbnail build, Takeout import, re-date) with their own cancel.
-3. **Folders**: the old Locations list. Row: path, mode as a dropdown suffix (Synced / On-demand, with
-   confirm when going on-demand deletes local copies), state subtitle, `Sync now` and a menu (Open,
-   Change location…, Pause this folder, Stop syncing…). "Add folder…" as a `ButtonRow` at the end.
-   The primary mount appears first and is not removable.
-4. **History**: the old Activity feed, with a kind filter, failures in `@error_color`, rows
-   activatable (open or reveal the target), and "Clear history".
-
-### Preferences dialog (slimmed Settings)
-
-| Page | Contents |
-|---|---|
-| General | Start on login; Mount location (path + Change…); Notifications (on sync issues, on import done) |
-| Storage | Cache usage bar; Cache budget (spin row, in GB, "Unlimited" switch instead of magic 0); Clear cache…; Offline files (count + "Manage" → Sync › Folders filter or a sub-page) |
-| Sync | Ignore patterns (editable list); Conflict clean-up: Off / Report / Remove identical copies (`conflict_sweep`); later: bandwidth limits |
-| Advanced | Open-with rules, search prompt config (only if kept in GUI) |
-
-Moved out: account row and Sign out (sidebar account menu, with confirm), quota (sidebar footer),
-mount status (sidebar status strip), live transfers (Sync), Google Photos import (Photos page menu),
-version/user agent (About → Debug info).
-
-## 4. Backend work required
-
-Everything below is new; nothing like it exists today.
-
-### B-1 Pause and resume (global, then per folder)
-
- `Request::SetSyncPaused { paused: bool, until: Option<i64> }`, persisted (config key
-  `sync_paused_until` or a DB setting) so a pause survives restarts; `Response::Status` gains
-  `paused` and `paused_until`.
- Drain: `run_pending_drain` (`pdfs-fuse/src/drain.rs:265`) already releases claimed ops while
-  offline; gate on `paused` at the same point and reuse the wake path.
- Sync engine: add `SyncMsg::Pause/Resume` or gate `reconcile_all` / `reconcile_folder`; the 120 s
-  poll and watcher keep recording, they just do not apply.
- FUSE reads must keep working while paused (on-demand hydration is a read, not a sync); document that
-  pause means "no uploads, no mirror reconcile".
- Per folder later: `sync_folder.paused` column, skipped in `reconcile_all`.
- Bandwidth limits later: token bucket in `CountingReader` / `CountingWriter`
-  (`pdfs-fuse/src/transfers.rs`).
-
-### B-2 Pending ops and transfers
-
- `Request::ListPendingOps` → id, kind, path/name, attempts, `last_error` (classified as
-  `ErrorKind`), `next_attempt_at`, parked flag, staged bytes.
- `Request::RetryOp { id }` (set `next_attempt_at = now`, wake drain) and `RetryAllFailing`.
- `Request::DiscardOp { id }` for a create/revision whose bytes should be dropped. Must save the
-  staged blob to a local recovery folder first; never silent data loss (see `docs/RECOVERY.md`).
- `TransferItem` gains a stable id and `Request::CancelTransfer { id }`.
- Per-folder last error message on `SyncFolderInfo` (today the text only exists in the activity feed).
-
-### B-3 Conflicts
-
- `Request::ListConflicts`: walk nodes whose name parses with `sweep.rs` `conflict_base_name`, for
-  the mount and every mirror folder. Return copy path, original path (if it exists), both sizes and
-  mtimes, whether content is identical (size + `content_sha1`, as the sweep already proves), and
-  which side is local vs remote when known.
- Optionally a `conflict` table written by `keep_as_conflict_copy` / `preserve_conflict_copy` so the
-  origin (drain vs mirror, device) is recorded instead of inferred from names.
- `Request::ResolveConflict { copy, keep: Original | Copy | Both }`:
-  - Original: trash the copy (re-verify like the enforcing sweep does).
-  - Copy: upload the copy's content as a new revision of the original, then trash the copy (the old
-    content stays in version history, so this is reversible).
-  - Both: rename the copy to a user-chosen name, drop the `(sync-conflict …)` stamp.
- Activity rows for each resolution.
-
-## 5. Shell and visual polish (all pages)
-
- **Per-page header bars.** Give each stack page its own `adw::ToolbarView` + `adw::HeaderBar` (or
-  inject page widgets into the shared bar on page switch). Title = page name, or the current folder
-  in My files. Page actions move into the header; the extra toolbar row disappears.
- **One page skeleton.** Same margins everywhere (today 12 vs 18), same `Clamp` rule (lists that are
-  settings-like clamp at 720, file/photo grids are full width), same status pages (`compact`,
-  `vexpand`, crossfade), same Retry semantics (Retry reloads; "Start Proton Drive" is a separate,
-  explicitly labelled button when the service is down).
- **Loading.** `adw::Spinner` in the header; keep the old model until the new one lands; status page
-  only on first load.
- **Theme.** Drop the global `accent_*` override; offer "Use Proton purple accent" in Preferences.
-  Replace hex colours with named colours; test light, dark and high contrast.
- **Move the 70-line CSS string** in `main.rs:232` to `resources/style.css` in the gresource
-  (`style-dark.css` if needed), so it can be edited and linted.
- **Shortcuts.** Replace the hand-rolled cheatsheet with `adw::ShortcutsDialog` (or
-  `GtkShortcutsWindow` before 1.8) listing all bindings, including F5/Ctrl+R and the viewer keys.
- **Toasts vs dialogs.** Dialogs report their own errors inline (versions, share, add bookmark); a
-  toast behind a modal is invisible. Pluralise properly (`ngettext`-ready helpers, no "item(s)").
- **i18n groundwork.** Wrap user strings in a `gettext!`-style macro now, even without translations,
-  so later localisation is mechanical.
-
-## 6. Page-by-page plan
-
-### My files
-
-Header: `[‹ ›]  Path bar (breadcrumbs, scroll to end, Ctrl+L to edit)  … [search] [view ▾] [+ New ▾]`
-
- **New ▾** (`list-add-symbolic`, suggested): New folder (Ctrl+Shift+N), Upload files (Ctrl+U),
-  Upload folder. Replaces three separate icons, fixes the "send" icon.
- **View ▾** split button: Grid/List (Ctrl+1/2), Sort by Name/Size/Modified, ascending/descending,
-  Folders first, zoom slider. Persist choice (config or GSettings).
- **Folder ⋮ menu** (in header or background context menu): Refresh, Build thumbnails, Make folder
-  available offline, Open in file manager, Share folder…. Build thumbnails leaves the main toolbar.
- **Navigation.** Back/forward history (Alt+←/→), Up (Alt+↑); searching then pressing Back clears
-  the search consistently.
- **Context menus** as `gtk::PopoverMenu` from `gio::Menu` + actions: keyboard navigable, Menu /
-  Shift+F10, same action set as details pane. Add a background menu. Order: Open, Open with…, Play
-  (media) · Available offline (check item) · Share…, Copy link · Rename…, Move to…, Versions… ·
-  Move to Trash (destructive).
- **Offline state.** One concept "Available offline", toggle semantics. Badges: cloud-only = no
-  badge or subtle `cloud-outline`; downloaded = check; available offline = pin/`folder-download`
-  style filled icon. Use named colours. Folders can be made available offline too, or the toggle is
-  hidden for them (fix `details.rs:259`).
- **List view.** Sortable, resizable columns: Name, Status, Size, Modified (date + time), and
-  Location for search results. Rubberband selection. One selection model shared between views.
- **Details pane.** On wide windows a real side pane (breakpoint, not overlay); header bar with
-  close; real thumbnail; sections: Info, Offline, Sharing (people count, link), Versions (latest 3 +
-  "All versions…"). Same actions as the context menu.
- **Selection bar** (≥1 selected, not ≥2): count + size, Available offline, Move to…, Share (single),
-  Move to Trash; Select all (Ctrl+A). Drop the confirm dialog for trash since Undo exists (trash is
-  reversible), or keep confirm and drop Undo — not both.
- **Drag and drop.** Drop external files/folders to upload (reuse Takeout's `FileList` target), drag
-  the whole selection, highlight drop targets, breadcrumbs accept drops, Undo toast on move.
- **Move to…** a folder-picker dialog (tree/list of Drive folders) instead of a free-text path.
- **Rename** pre-selects the stem, not the extension; drop the redundant "Rename “x”." body.
- **Search.** Scope toggle (This folder / Everywhere), "Showing first 200 results" note, Location
-  column, correct cached badges (search hits hardcode `cached: false`).
- **Upload feedback.** Toast "Uploading 3 items" with "View" → Sync › Transfers.
-
-### Photos (was Gallery)
-
- Header: title "Photos", `InlineViewSwitcher` Timeline | Albums in the header, Select toggle,
-  `+ Upload` (fix: use `adw::ButtonContent`, today `.icon_name()` overwrites `.label()` at
-  `photos.rs:426-432`), ⋮ menu: Import from Google Photos…, Refresh, Rebuild library.
- Filters: a single filter dropdown/`ToggleGroup` (All, Photos, Videos, RAW, Favorites) instead of
-  two segmented rows where "Photos" appears twice. Counts follow the active filter.
- **Month scrubber** on the right edge that *jumps* (not filters); the month dropdown becomes a real
-  "Filter by date" if kept.
- Infinite scroll with prefetch (no "Load more" pill; page size ≥ 200; also trigger when the first
-  page does not fill the viewport).
- Tiles: `ContentFit::Cover` (crop) in justified rows, known aspect ratio from metadata to prevent
-  reflow, placeholder as a tinted card of the final size, subtle hover (no 1.06 scale with heavy
-  shadow on a 2 px gap grid), last row justified up to a max stretch.
- Context menu on tiles: Open, Favorite, Add to album, Download/Save copy, Show in My files, Move to
-  Trash. Selection: Shift range, Ctrl+A, bulk Favorite, Add to album, Download.
- Empty states per filter ("No favorites yet", "No videos in June 2024") instead of the global
-  "No photos yet" with upload buttons.
- Import: runs show a banner on Photos ("Importing from Google Photos — 1,204 of 5,000 · View") and
-  Back returns to where the user came from.
- **Albums:** Create, rename, delete, remove from album (not trash). Fix state bugs: filter row
-  hidden on the album grid, subtitle count, scroll position kept when switching back.
- **Viewer:** `adw::Window` (or full-window overlay), controls auto-hide after 2 s idle, zoom/pan
-  (pinch, Ctrl+scroll, double-click), info panel beside the image instead of over the top bar,
-  pages beyond the loaded 60, counter against the real total, videos play inline with
-  `gtk::Video`, trash with the same confirm/undo rule as the grid, real filename in "Save a copy",
-  success toast, "Open with…" app chooser, favorite tooltip reflects state, readable dates.
-
-### Shared with me / Shared by me
-
- Shared with me: header title shows the drill-down path, with back; invitations as a banner at
-  the top ("2 invitations · Review") opening a list, Reject confirmed; bookmarks become a separate
-  view or section via a switcher. Rows: Open, Save to My files, Available offline where supported.
- Shared by me: rows activatable (open), suffix "Manage" becomes a menu with Copy link, Manage
-  access…, Stop sharing….
- Share dialog: inline validation, loading spinner, confirm "Remove access" and "Delete link",
-  human role names, link expiry.
-
-### Computers
-
- Show the real device name for "This computer" with rename inline.
- Other computers: one suffix menu (Rename, Use this identity…, Remove…). Remove uses a destructive
-  confirm that requires typing the device name since it deletes backups.
- "Restore folders" becomes a per-device action ("Restore to this computer…") with an inline-empty
-  state when nothing is restorable, and moves the "Add folder" responsibility fully to Sync.
- Terminology: "computer" everywhere in UI copy.
-
-### Trash
-
- Same skeleton as other list pages (clamped `boxed-list`), sort by deleted date, multi-select with
-  Restore / Delete permanently, "Empty Trash…" moved into a header ⋮ menu or kept as a flat button
-  with a destructive confirm, proper plurals, Retry on error.
-
-### Login
-
- Human error messages mapped from error kinds, spinner in the button, "Create account" and "Forgot
-  password" links, recovery-code hint in 2FA, cancelling CAPTCHA returns to the form with a message.
-
-## 7. Tray
-
- Symbolic icon variants: `pdfs-synced`, `pdfs-syncing`, `pdfs-paused`, `pdfs-offline`,
-  `pdfs-attention`; tooltip with the one-line state; `NeedsAttention` status for issues.
- Menu: status line · "N issues — View" (opens Sync › Issues) · Pause sync ▸ (1 h, until tomorrow,
-  until resumed) / Resume · Open Proton Drive · Open folder · "Sign in…" when logged out (no
-  "Connect") · Stop Proton Drive (confirm) · "Hide tray icon" instead of "Quit" (daemon keeps
-  running and the label must not suggest otherwise).
-
-## 8. Glossary (one term, one icon)
-
-| Concept | UI term | Icon |
-|---|---|---|
-| Root of Drive | My files | `folder-symbolic` |
-| Background service | Proton Drive (running / stopped) — never "daemon" or "mount service" in UI | — |
-| Cloud-only file | Online only | none / `cloud-outline` |
-| Pinned file | Available offline | pin/download-filled custom icon, not stars |
-| Upload | Upload files / Upload folder | `document-upload`-style arrow up, custom pair |
-| Folder sync mode | Synced / Online only | — |
-| Where My files appears on disk | Proton Drive folder — never "mountpoint" in UI | — |
-| Stop syncing a folder | Stop syncing… | `media-playback-stop-symbolic` in a menu, not trash |
-| Remove a computer | Remove computer… | destructive, in menu |
-| Conflict copy | Conflict | `dialog-warning-symbolic` + warning colour |
-| Failure | Failed / Needs attention | `dialog-error-symbolic` + error colour |
-| Pause | Pause sync / Resume sync | `media-playback-pause-symbolic` / `-start-` |
-| Photos section | Photos | `image-x-generic-symbolic` |
-| Sharing | Shared by me / Shared with me | distinct icons (`emblem-shared` / `folder-publicshare`) |
-
-Spelling: US English throughout ("Favorite", "color"), matching the `pdfs favorite` command and
-Proton's own apps. Title Case for
-dialog headings and buttons in dialogs, Sentence case for menu items and rows (HIG).
-
-## 9. Bugs found during the audit (quick wins)
-
-1. Photos Upload pill loses its label (`photos.rs:426-432`); same for viewer "Show on map"
-   (`photo_viewer.rs:594-598`).
-2. Takeout Back always goes to Settings, sidebar highlights Settings when opened from Photos
-   (`main.rs:779`, `takeout.rs:131-136`).
-3. Thumbnail-build completion message computed then hidden (`browser.rs:1632-1667`).
-4. Search results show cached files as cloud-only (`browser.rs:2344`).
-5. Details "Available offline" switch shown for folders (`details.rs:259`).
-6. Grid and list keep separate selections; details pane can describe a hidden-view item.
-7. F2 silently does nothing with multiple items selected.
-8. Filter changes on the Albums grid swap to the timeline while the Albums toggle stays active
-   (`photos.rs:958-997`).
-9. Subtitle "60 photos" next to "All 1,416" (loaded count vs total, `photos.rs:2007-2015`); viewer
-   counter "12 of 60".
-10. Viewer info panel covers Close/Trash/Save (`photo_viewer.rs:588` vs `648`).
-11. Locations mode switch and removal reload Computers, not Locations; a rejected mode switch stays
-    flipped until the next tick (`devices.rs:612`, `devices.rs:809`, `locations.rs:374`).
-12. Going on-demand deletes local copies without confirmation.
-13. Retry on Not-connected silently restarts the systemd unit; Locations' Retry does not.
-14. Toasts from Versions/Share dialogs land behind the modal.
-15. "Emptied trash —" dangling dash, "item(s)", "archive(s)", raw revision id as version title,
-    raw lowercase link role.
-16. Bulk context menu shows a separator directly under the header when a folder is selected.
-17. Sign out, Reject invitation, Remove access, Delete link, tray Disconnect: no confirmation.
-18. Stale doc comments (`devices.rs:46-48`, `locations.rs:329-331`, `albums.rs:4`,
-    `browser.rs:1155`).
-
-## 10. Phased roadmap
-
-Each phase is shippable on its own. Estimates are rough, for one developer.
-
-| Phase | Content | Crates | Size |
-|---|---|---|---|
-| 0 Quick wins | Section 9 bugs, glossary wording, icon swaps (upload, offline, stop syncing), confirmations, plurals | gui, tray | S (2–3 days) |
-| 1 Shell | libadwaita feature bump, per-page header bars, sidebar restructure + footer (status, quota, account), Preferences dialog, About debug info, theme/colour cleanup, CSS to gresource, shortcuts dialog | gui | M (1 week) |
-| 2 Sync hub + pause | B-1 global pause, B-2 list/retry pending ops, Sync page (status card, Issues, Transfers, Folders, History), tray states and pause menu, GUI uses `failing_*` / `parked_*` | core, fuse, gui, tray, cli | L (1.5–2 weeks) |
-| 3 Conflicts | B-3 list + resolve, Issues rows with a compare/resolve dialog (both versions side by side: size, date, device, preview for images/text), CLI `pdfs conflicts` | core, fuse, gui, cli | M–L |
-| 4 File browser | Header layout, New menu, sort/persisted view, PopoverMenu context menus, details side pane, DnD upload, folder picker for Move, search scope | gui | L |
-| 5 Photos | Rename, header switcher, filters, infinite scroll + scrubber, tile layout, context menu, album management, viewer rewrite (auto-hide, zoom, inline video) | gui (+ core for album mutations) | L |
-| 6 Rest | Shared pages, Computers, Trash, Login, per-folder pause, bandwidth limits, i18n wrapping | all | M |
-
-Phase 2 is where the user-reported gaps (pause, resume, stuck items) get closed; phase 3 closes the
-conflict overview. Phases 0–1 fix most of the "unpolished" impression cheaply and should come first
-because later phases build on the new header/page skeleton.
-
-### Verification per phase
-
- `cargo fmt --all -- --check`, `cargo clippy --workspace --all-targets -- -D warnings`,
-  `cargo test --workspace`.
- Backend phases: DB migration tests in `crates/pdfs-core/src/db/tests.rs` (paused state, conflict
-  table if added), drain tests proving no op is claimed while paused, resolve-conflict tests proving
-  the losing side stays recoverable (trash or version history).
- GUI phases: before/after screenshots in `images/` (light and dark), keyboard-only walkthrough of
-  each page, narrow-window check (sidebar collapse breakpoint).
@@ -7,6 +7,7 @@ How Proton Drive for Linux works and how to use it day to day. For installation
 - [My files](#my-files)
 - [Keeping files on this computer](#keeping-files-on-this-computer)
 - [Syncing local folders](#syncing-local-folders)
+- [Changes waiting for Proton Drive](#changes-waiting-for-proton-drive)
 - [Conflicts](#conflicts)
 - [Pausing and limiting sync](#pausing-and-limiting-sync)
 - [Photos](#photos)
@@ -33,7 +34,7 @@ the service to do things over a local socket:

 Your Drive, your file names and your photos are end-to-end encrypted by Proton. On this computer,
 the service must decrypt what it shows you, and it keeps a decrypted cache and index on disk. Use
-full-disk or home-directory encryption. [ARCHITECTURE.md §8](ARCHITECTURE.md#8-threat-model-what-this-client-writes-to-disk-in-plaintext)
+full-disk or home-directory encryption. [ARCHITECTURE.md §10](ARCHITECTURE.md#10-threat-model-what-this-client-writes-to-disk-in-plaintext)
 lists exactly what is stored.

 The app uses these words consistently, and so does this guide:
@@ -54,9 +55,11 @@ downloads only when a program reads it:

 - **Reads fetch only what is needed.** A video player that seeks, or a tool that reads a file
  header, downloads only those parts. Media streams while it plays.
- **Writes are safe offline.** When a program closes a file it wrote, the service stores the new
-  content on disk and queues the upload. The queue survives network loss, restarts and crashes.
-  `pdfs sync queue` lists what has not reached Proton Drive yet.
+- **Changes work at local speed.** Creating, renaming, moving and deleting files and folders
+  returns at once, online or offline. When a program closes a file it wrote, the new content is
+  stored on disk. Every change is queued and sent to Proton Drive in the background; the changes
+  to one file are sent in the order you made them. The queue survives network loss, restarts and
+  crashes. See [Changes waiting for Proton Drive](#changes-waiting-for-proton-drive).
 - **Recently read content is cached** on disk up to the cache size limit (5 GiB by default) and
  evicted oldest first.
 - **Items shared with you** appear under `Shared with me/` inside the Proton Drive folder. Shares
@@ -95,6 +98,28 @@ of the folder, so the files stay visible but take no disk space until opened. Sw
 **Synced / Online only** switch on the folder's card, or `pdfs sync mode <id> ondemand` and back
 with `pdfs sync mode <id> mirror`. `pdfs locations` lists every local place the service occupies.

+### Moving between synced folders and My files
+
+`~/ProtonDrive` and each online-only folder are separate mounts, and a mirrored folder is a plain
+folder on disk. `mv`, and dragging in a file manager, cannot rename across them, so they copy
+and then delete: every file is downloaded, uploaded again, and the original goes to the Trash.
+
+Use `pdfs move <path> <folder>` or **Move to…** in the app instead. The move happens on Proton
+Drive, so it takes seconds whatever the size. For example:
+
+```sh
+pdfs move ~/Documents/Scans ~/ProtonDrive/Archive
+pdfs move ~/Documents/a.pdf ~/Documents/b.pdf ~/ProtonDrive/Archive
+```
+
+The last path is the destination folder; everything before it moves there.
+Files already opened in an online-only folder are not downloaded again when
+they move into a mirrored one.
+
+A move out of a synced folder waits until its files are on Proton Drive. A file that is still
+uploading, has changes that are not uploaded, or is excluded by `.pdfsignore` stops the move,
+and the message names it.
+
 Removing a synced folder (**Stop Syncing** or `pdfs sync rm <id>`) keeps the local files and the
 copy on Proton Drive. Add `--delete-remote` (or tick **Also delete from Proton Drive**) to delete
 the copy on Proton Drive as well.
@@ -121,6 +146,36 @@ places, and both apply:
 Rules are re-read on every pass. Ignoring never deletes anything: a file that becomes ignored is
 simply no longer tracked, and its copy on Proton Drive stays.

+## Changes waiting for Proton Drive
+
+A change you made in the Proton Drive folder exists only on this computer until it reaches
+Proton Drive. `pdfs status`, the tray and **Sync → Overview** count what is still waiting, and
+`pdfs sync queue` lists it.
+
+Sometimes Proton Drive refuses a change: the storage is full, a share was taken away, the folder
+is gone, the folder holds too many items, or Drive does not accept a name. The change then needs
+your attention. It shows at once in **Sync → Overview**, in the tray, and in `pdfs sync issues`,
+with what it means and what you can do. A file or folder with such a change carries a warning
+badge in **Files**; hover it to see why.
+
+Nothing is deleted. The change stays queued and is retried. You can:
+
+- **Retry** it now, from the same list or with `pdfs sync retry`, for example after freeing space.
+- **Export** a file's content to keep your version (`pdfs sync export <id> <file>`).
+- **Discard** the change (`pdfs sync discard <id>`). It is undone here and never sent: a new file
+  or folder goes away, anything else goes back to what Proton Drive has. Export first if you want
+  to keep the content.
+
+Two cases are not refused, and the activity log records both:
+
+- A new file or folder whose name is already taken on Proton Drive by something this computer had
+  not seen yet lands under a `(sync-conflict …)` name, as described below.
+- A new file whose folder was deleted on another device meanwhile lands at the top of My files,
+  so its content is not lost.
+
+Before you shut down a computer for good, check that nothing is waiting: see
+[RECOVERY.md](RECOVERY.md#lost-with-the-machine).
+
 ## Conflicts

 When the same file changed on this computer and somewhere else since the last sync, neither side
@@ -144,7 +199,6 @@ The version you do not keep goes to the Trash, so a wrong choice can be undone.
  reading files keeps working. `pdfs sync resume` continues.
 - **Limit bandwidth** under **Preferences → General → Network**, or with
  `pdfs sync limit --up 2M --down 10M`. `0` removes a limit.
- **Retry** a failed upload from **Sync → Overview**, or with `pdfs sync retry`.

 ## Photos

@@ -235,6 +289,15 @@ The window stays loaded after the first use, so later shortcuts open it instantl
 and video open straight from the Proton Drive folder, so players can start before the whole file
 downloads. Other Drive files download first, then open.

+To make the first shortcut instant as well, start the launcher hidden with your session.
+`pdfs-prompt --preload` loads the window without showing it and does nothing if the launcher is
+already running. For Hyprland:
+
+```ini
+exec-once = pdfs-prompt --preload
+bind = SUPER, space, exec, pdfs-prompt
+```
+
 ### Using your own launcher

 `pdfs-prompt --dmenu` shows the results in fuzzel, rofi, wofi, tofi, bemenu or dmenu, whichever is
@@ -0,0 +1,156 @@
+<svg width="1920" height="1080" viewBox="0 0 1920 1080" xmlns="http://www.w3.org/2000/svg">
+  <defs>
+    <linearGradient id="bg" x1="0" y1="0" x2="1920" y2="1080" gradientUnits="userSpaceOnUse">
+      <stop offset="0" stop-color="#1A1240"/>
+      <stop offset="1" stop-color="#0A0618"/>
+    </linearGradient>
+    <radialGradient id="glow1" cx="1390" cy="520" r="640" gradientUnits="userSpaceOnUse">
+      <stop offset="0" stop-color="#6D4AFF" stop-opacity="0.55"/>
+      <stop offset="0.5" stop-color="#6D4AFF" stop-opacity="0.15"/>
+      <stop offset="1" stop-color="#6D4AFF" stop-opacity="0"/>
+    </radialGradient>
+    <radialGradient id="glow2" cx="160" cy="1080" r="700" gradientUnits="userSpaceOnUse">
+      <stop offset="0" stop-color="#A855F7" stop-opacity="0.25"/>
+      <stop offset="1" stop-color="#A855F7" stop-opacity="0"/>
+    </radialGradient>
+    <pattern id="dots" width="32" height="32" patternUnits="userSpaceOnUse">
+      <circle cx="2" cy="2" r="1.6" fill="#FFFFFF"/>
+    </pattern>
+    <radialGradient id="dotfade" cx="1390" cy="520" r="900" gradientUnits="userSpaceOnUse">
+      <stop offset="0" stop-color="#FFFFFF" stop-opacity="1"/>
+      <stop offset="1" stop-color="#FFFFFF" stop-opacity="0"/>
+    </radialGradient>
+    <mask id="dotmask" maskUnits="userSpaceOnUse" x="0" y="0" width="1920" height="1080">
+      <rect width="1920" height="1080" fill="url(#dotfade)"/>
+    </mask>
+    <linearGradient id="title2" x1="140" y1="0" x2="760" y2="0" gradientUnits="userSpaceOnUse">
+      <stop offset="0" stop-color="#C9BBFF"/>
+      <stop offset="1" stop-color="#8A6CFF"/>
+    </linearGradient>
+
+    <!-- app logo -->
+    <linearGradient id="pdl-face" x1="12" y1="12" x2="116" y2="112" gradientUnits="userSpaceOnUse">
+      <stop offset="0" stop-color="#A48BFF"/>
+      <stop offset="0.55" stop-color="#7552FF"/>
+      <stop offset="1" stop-color="#5B36F2"/>
+    </linearGradient>
+    <linearGradient id="pdl-cloud" x1="0" y1="34" x2="0" y2="88" gradientUnits="userSpaceOnUse">
+      <stop offset="0" stop-color="#FFFFFF"/>
+      <stop offset="1" stop-color="#ECE6FF"/>
+    </linearGradient>
+    <mask id="pdl-cut" maskUnits="userSpaceOnUse" x="0" y="0" width="128" height="128">
+      <g fill="#FFFFFF">
+        <circle cx="66" cy="57" r="23"/>
+        <circle cx="42" cy="68" r="16"/>
+        <circle cx="88" cy="69" r="15"/>
+        <rect x="26" y="68" width="77" height="20" rx="10"/>
+      </g>
+      <g stroke="#000000" stroke-width="7.5" stroke-linecap="round" stroke-linejoin="round" fill="none">
+        <path d="M64 49v26"/>
+        <path d="M54.5 65.5l9.5 9.5 9.5-9.5"/>
+      </g>
+    </mask>
+    <filter id="logoshadow" x="-50%" y="-50%" width="200%" height="200%">
+      <feGaussianBlur stdDeviation="6"/>
+    </filter>
+    <filter id="chipshadow" x="-50%" y="-50%" width="200%" height="200%">
+      <feGaussianBlur stdDeviation="14"/>
+    </filter>
+  </defs>
+
+  <!-- background -->
+  <rect width="1920" height="1080" fill="url(#bg)"/>
+  <rect width="1920" height="1080" fill="url(#glow2)"/>
+  <rect width="1920" height="1080" fill="url(#glow1)"/>
+  <rect width="1920" height="1080" fill="url(#dots)" opacity="0.07" mask="url(#dotmask)"/>
+
+  <!-- orbit rings -->
+  <g fill="none" stroke="#FFFFFF">
+    <circle cx="1390" cy="520" r="300" stroke-opacity="0.10" stroke-width="2"/>
+    <circle cx="1390" cy="520" r="420" stroke-opacity="0.06" stroke-width="2" stroke-dasharray="4 14" stroke-linecap="round"/>
+  </g>
+
+  <!-- logo, 128 -> 384 -->
+  <g transform="translate(1198 328) scale(3)">
+    <rect x="16" y="24" width="96" height="92" rx="24" fill="#2A1080" opacity="0.8" filter="url(#logoshadow)"/>
+    <rect x="12" y="16" width="104" height="100" rx="26" fill="#4424C0"/>
+    <rect x="12" y="12" width="104" height="100" rx="26" fill="url(#pdl-face)"/>
+    <rect x="12.5" y="12.5" width="103" height="99" rx="25.5" fill="none" stroke="#FFFFFF" stroke-opacity="0.2"/>
+    <rect y="3" width="128" height="128" fill="#2E1596" fill-opacity="0.3" mask="url(#pdl-cut)"/>
+    <rect width="128" height="128" fill="url(#pdl-cloud)" mask="url(#pdl-cut)"/>
+  </g>
+
+  <!-- feature chips around the logo -->
+  <g font-family="Adwaita Sans" font-size="26" font-weight="600" fill="#FFFFFF">
+    <!-- folder, top left -->
+    <g transform="translate(1000 200)">
+      <rect x="0" y="10" width="236" height="76" rx="22" fill="#000000" opacity="0.35" filter="url(#chipshadow)"/>
+      <rect x="0" y="0" width="236" height="76" rx="22" fill="#2A2058" fill-opacity="0.85" stroke="#FFFFFF" stroke-opacity="0.14" stroke-width="1.5"/>
+      <g transform="translate(22 20)">
+        <rect width="36" height="36" rx="10" fill="#6D4AFF"/>
+        <path d="M8 13a2 2 0 0 1 2-2h5l2.5 2.5H26a2 2 0 0 1 2 2V25a2 2 0 0 1-2 2H10a2 2 0 0 1-2-2z" fill="#FFFFFF"/>
+      </g>
+      <text x="74" y="47">On demand</text>
+    </g>
+    <!-- sync, top right -->
+    <g transform="translate(1590 290)">
+      <rect x="0" y="10" width="164" height="76" rx="22" fill="#000000" opacity="0.35" filter="url(#chipshadow)"/>
+      <rect x="0" y="0" width="164" height="76" rx="22" fill="#2A2058" fill-opacity="0.85" stroke="#FFFFFF" stroke-opacity="0.14" stroke-width="1.5"/>
+      <g transform="translate(22 20)">
+        <rect width="36" height="36" rx="10" fill="#1EA885"/>
+        <g fill="none" stroke="#FFFFFF" stroke-width="2.6" stroke-linecap="round" stroke-linejoin="round">
+          <path d="M26 15a8.5 8.5 0 0 0-15-2"/>
+          <path d="M10 9v4.5h4.5"/>
+          <path d="M10 21a8.5 8.5 0 0 0 15 2"/>
+          <path d="M26 27v-4.5h-4.5"/>
+        </g>
+      </g>
+      <text x="74" y="47">Sync</text>
+    </g>
+    <!-- photos, bottom right -->
+    <g transform="translate(1560 690)">
+      <rect x="0" y="10" width="206" height="76" rx="22" fill="#000000" opacity="0.35" filter="url(#chipshadow)"/>
+      <rect x="0" y="0" width="206" height="76" rx="22" fill="#2A2058" fill-opacity="0.85" stroke="#FFFFFF" stroke-opacity="0.14" stroke-width="1.5"/>
+      <g transform="translate(22 20)">
+        <rect width="36" height="36" rx="10" fill="#E8618C"/>
+        <rect x="8" y="9" width="20" height="18" rx="3" fill="none" stroke="#FFFFFF" stroke-width="2.4"/>
+        <circle cx="14" cy="15" r="2" fill="#FFFFFF"/>
+        <path d="M9.5 25l6-6 4 4 3-3 4 4" fill="none" stroke="#FFFFFF" stroke-width="2.4" stroke-linejoin="round"/>
+      </g>
+      <text x="74" y="47">Photos</text>
+    </g>
+    <!-- terminal, bottom left -->
+    <g transform="translate(980 790)">
+      <rect x="0" y="10" width="206" height="76" rx="22" fill="#000000" opacity="0.35" filter="url(#chipshadow)"/>
+      <rect x="0" y="0" width="206" height="76" rx="22" fill="#2A2058" fill-opacity="0.85" stroke="#FFFFFF" stroke-opacity="0.14" stroke-width="1.5"/>
+      <g transform="translate(22 20)">
+        <rect width="36" height="36" rx="10" fill="#3B3F5C"/>
+        <path d="M9 12l6 6-6 6" fill="none" stroke="#FFFFFF" stroke-width="2.6" stroke-linecap="round" stroke-linejoin="round"/>
+        <path d="M18 25h9" stroke="#FFFFFF" stroke-width="2.6" stroke-linecap="round"/>
+      </g>
+      <text x="74" y="48" font-family="JetBrainsMono NF" font-size="25" font-weight="700">pdfs</text>
+      <text x="150" y="48" font-weight="500" fill="#B9B0D9">CLI</text>
+    </g>
+  </g>
+
+  <!-- text block -->
+  <g font-family="Adwaita Sans">
+    <g transform="translate(140 292)">
+      <rect width="410" height="48" rx="24" fill="#6D4AFF" fill-opacity="0.18" stroke="#8A6CFF" stroke-opacity="0.6" stroke-width="1.5"/>
+      <circle cx="28" cy="24" r="6" fill="#A48BFF"/>
+      <text x="46" y="32" font-size="21" font-weight="700" letter-spacing="2.4" fill="#D6CCFF">UNOFFICIAL · OPEN SOURCE</text>
+    </g>
+    <text x="134" y="478" font-size="124" font-weight="800" letter-spacing="-3" fill="#FFFFFF">Proton Drive</text>
+    <text x="134" y="610" font-size="124" font-weight="800" letter-spacing="-3" fill="url(#title2)">for Linux</text>
+    <text x="140" y="702" font-size="38" font-weight="400" fill="#B9B0D9">Your Drive as a folder, and a native GTK4 app.</text>
+    <text x="140" y="752" font-size="38" font-weight="400" fill="#B9B0D9">No Electron.</text>
+  </g>
+
+  <!-- footer -->
+  <g font-family="JetBrainsMono NF" font-size="24" fill="#8C83B0">
+    <text x="140" y="968">github.com/narrrl/proton-drive-linux</text>
+  </g>
+  <g font-family="Adwaita Sans" font-size="22" fill="#6F6894">
+    <text x="1780" y="968" text-anchor="end">Not affiliated with Proton AG</text>
+  </g>
+</svg>
@@ -9,11 +9,11 @@
 # Build + install:   cd packaging && makepkg -fi

 pkgname=proton-drive-linux
-pkgver=2.6.0
+pkgver=3.1.0
 pkgrel=1
 pkgdesc="Unofficial Proton Drive client for Linux: files-on-demand FUSE mount, CLI, GTK4 app + tray"
 arch=('x86_64')
-url="https://github.com/narrrl/proton-drive-linux"
+url="https://proton-drive.narl.io"
 license=('MIT')
 depends=('fuse3' 'gtk4' 'libadwaita' 'webkitgtk-6.0' 'perl-image-exiftool')
 makedepends=('cargo' 'git' 'gettext')