fix(fuse,core): keep a rename made while its create is on the wire

A rename of a node whose create is still queued rewrites the create's
target, but the drain had already copied the op. When the create
landed, the row was deleted unread and the rename was lost (B136).

finish_create now learns where the create was sent and where it landed,
and queues a rename of the real uid when the row has moved on since.
adopt_real_uid keeps the tree's name and folder while that rename is
queued. A landed folder's children also stop naming its placeholder as
their parent in memory, which put the placeholder back on their rows.

docs/BUGS.md

@@ -12,6 +12,35 @@ Conventions:
 
 ---
 
+## B136 — A file renamed while its first upload is on the wire goes back to its old name
+
+**Status:** Fixed (unverified).
+**Found:** 2026-10-03, by the simulation runs (`sim::run`, profile one-client-flaky, seed 3), at
+the end check for lost data. A file made offline was renamed after the drain had taken its create.
+The create landed under the old name and the new name was gone. Every replay of the seed.
+
+**Where:** `Db::finish_create` in `crates/pdfs-core/src/db/ops.rs`, `drain_local_node` and
+`adopt_real_uid` in `crates/pdfs-fuse/src/drain.rs`.
+
+**Cause.** A rename of a node whose create is still queued rewrites the create's parent and name
+(`Db::rewrite_op_target`) instead of queuing a rename. The drain copies the op when it takes it,
+so a rewrite while the create was on the wire changed only the row. When the create landed,
+`finish_create` deleted the row without looking at it again, and `adopt_real_uid` put the node
+back where Drive had it. The move was lost on Drive and in the tree.
+
+The same seed showed a second fault. When a folder made offline landed, the nodes in it still
+named the folder's placeholder uid as their parent in memory. The next write of one of them put
+the placeholder back on its row.
+
+**Fix.** The drain passes where it sent the create and where it landed (a conflict name, or the
+root when the folder was gone) to `finish_create`. When the row names another parent or name than
+it was sent with, the same transaction queues a rename of the real uid to it, with the landed
+parent and name as the original ones. `adopt_real_uid` keeps the tree's name and parent while
+that rename is queued. When a node lands, its children's parent is changed to its real uid.
+
+**Test:** the unit test `a_rename_made_while_its_create_uploads_is_queued_for_the_landed_node`.
+Seed 3 of one-client-flaky passes.
+
 ## B135 — A file just moved is sometimes not found by its new path
 
 **Status:** Fixed (unverified).