feat(core,fuse,cli,gui): report changes Drive refuses as 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 the change was rejected
used to look like any other failure until six attempts had passed. The
drain now sorts the refusal into an issue and stores it on the queued op
(schema 38), so it needs attention at once in the app, tray and CLI. The
change stays queued and is retried; nothing is deleted.

The queue listing carries the issue and whether the op has file content.
ExportPendingOp copies that content to a new file: the Sync page offers it
as an Export button next to each issue, and the CLI as
`pdfs sync export <id> <dest>`. `pdfs sync issues` lists what needs
attention, and `pdfs sync queue` shows the issue per change.

docs/MILESTONE-3.0.0-STATUS.md tracks what is left for 3.0.0.

docs/CHANGELOG.md

@@ -11,8 +11,18 @@ scratch (user data in `staging/` and `recovery/` is never touched by this).
 
 ## [Unreleased]
 
-Schema: **37**. The queue table is rebuilt so an id is never given out twice; queued changes
-are kept.
+Schema: **38**. 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.
+
+### 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.
 
 ### Changed
 - **Making, renaming and deleting through the mount no longer waits for Drive.** A new folder,

docs/MILESTONE-3.0.0-STATUS.md

@@ -0,0 +1,52 @@
+# 3.0.0: what is done and what is left
+
+Tracks `docs/MILESTONE-3.0.0.md`. Update it with every commit that moves a phase.
+
+## Done
+
+- **Phase 0**: fake Drive, simulation runs, CI job (2.9.0).
+- **Phase 1**: queued-op preconditions and own sealed revisions in the database (2.9.0).
+- **Phase 2**: local ids, inode = local id, one tree for every mount (2.10.0).
+- **Phase 3, first part**: mkdir, create, rename, unlink and rmdir on the mount are recorded
+  locally and sent from the queue; `"local_first": false` brings back the old path (5e0f30c).
+- Fixes from the simulation and account runs since then: B141 to B147.
+- **Sync issues, first cut** (§6.2): refusals sorted into issues, shown at once in the app,
+  tray and CLI; Export button and `pdfs sync export`; `pdfs sync issues`.
+
+## Phase 3: left for 3.0.0
+
+1. **Sync issues (§6.2)**: first cut done.
+   - [x] The drain sorts a refusal from Drive into an issue kind (quota, access, missing,
+         limit, rejected) and stores it on the queued op (schema 38).
+   - [x] An op with an issue counts as "needs attention" at once, not after six failures.
+   - [x] The queue listing carries the issue kind and whether its content can be exported.
+   - [x] Export a queued file's content (control request, `pdfs sync export`).
+   - [x] `pdfs sync issues`, and the issue shown in `pdfs sync queue`.
+   - [x] The app's Sync page shows each issue with what the user can do; Export and Retry
+         buttons; translated in every catalog.
+   - [ ] Discard an issue on purpose (after export, or for a change with no content), and
+         undo the local change it stood for. Not in the first cut.
+   - [ ] Show the issue on the node itself (file browser emblem or status). Not in the first
+         cut.
+2. **Planner and executor (§5.4, §5.5)**: ops keyed by local id; remove `mint_local_uid`,
+   `finish_create` and `adopt_real_uid`; a landing create sets `remote_uid` on its row.
+3. **Speed (§7)**: run independent ops in parallel, batch trashes and moves; measure 1,000 files
+   and 100 folders on Wi-Fi against LAN (target: within 10 %).
+4. **Done-when checks**:
+   - [ ] Simulation passes on the Wi-Fi profile.
+   - [ ] Known-bug list in `sim/run.rs` is empty: B125 and B130 open; B129 and B132 fixed but
+         unconfirmed.
+   - [ ] A clean account run. The last one (2026-10-04) failed on B70 (fixed as B145) and
+         mirror/mirror "busy syncing" (the script now retries); not confirmed yet.
+5. **Release**: the 2.9.0 and 2.10.0 tags still wait for the user's go-ahead.
+
+## After 3.0.0
+
+- Remove the old online path in `filesystem.rs` and the `local_first` switch (the release after
+  3.0.0).
+- **Phase 4**: one applier for remote changes.
+- **Phase 5**: mirror folders on the same planner and executor.
+- **Any time**: `Size` and block geometry as types; a `Deadline` on every remote call.
+- Open questions in §12 of the milestone.
+- `PLAN.md`: the acceptance script notices network drops and reports `interrupted` instead of
+  TIMEOUT.