# Objective

`WorktreeStore::find_or_create_worktree` inserts the shared
worktree-creation task into `loading_worktrees` and relies on the task
it returns to each caller to remove that entry once creation resolves.
But the creation task keeps running through the clone the map itself
holds, while the map cleanup lives only in the callers' returned tasks.

If every caller is cancelled before creation resolves, the resolved task
stays in `loading_worktrees` forever, retaining the `Entity<Worktree>`
captured in its result (a `Shared` task memoizes its output). Such a
worktree can never be released: `remove_worktree` only unlists it, so
its background scan keeps running and its snapshot keeps growing for the
lifetime of the window. The stale entry also keeps
`initial_scan_complete` permanently `false` (that flag is
`loading_worktrees.is_empty() && …`).

Callers are cancelled routinely — worktree creation is async and can
take seconds on a large tree, while the tasks awaiting it are owned by
UI that the user can close at any time (a tab or pane, a debugger panel
resolving a path, an agent session, or the whole window). See the
existing note in `crates/zed/src/zed.rs` that external-file worktrees
are "released on file close".

Observed in the wild: a home-directory worktree removed from the project
kept scanning for hours and grew Zed past 45 GB; neither removing the
folder nor ending the agent session freed it — only quitting Zed. (The
scan-amplification half of that incident is #60988.)

## Solution

Spawn the map cleanup as its own detached task, next to the map
insertion, so a loading entry always leaves `loading_worktrees` when
loading resolves regardless of what happens to the callers. The returned
per-caller task is unchanged apart from no longer owning that cleanup.

## Testing

- Added `test_worktree_released_when_creation_caller_is_cancelled`: it
requests a worktree, drops the returned task immediately (as a cancelled
caller would), lets creation complete, removes the worktree, and asserts
the entity is released. It fails on `main` and passes with this change.
- Full worktree-related project integration suite is green (45/45).

## Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content adheres to Zed's UI standards
([UX/UI](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
and
[icon](https://github.com/zed-industries/zed/blob/main/crates/icons/README.md)
guidelines)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

Release Notes:

- Fixed a memory leak where a worktree whose creation was requested by a
since-cancelled task (e.g. a folder opened as its owning
tab/panel/window closed) could never be released, leaving its background
scan running and its snapshot growing for the lifetime of the window.

---------

Co-authored-by: Kirill Bulatov <kirill@zed.dev>