## Why
Concurrent Linux test spawns can inherit writable descriptors for executable fixtures, preventing those fixtures from being executed even after the writing test closes its descriptor.
## What changed
Replace direct executable fixture writes and copies across the Rust tests with `codex_utils_cargo_bin::write_executable` and `copy_executable`. These existing helpers complete writes and copies in separate processes on Linux.
Remove the empty temporary inode before creating fake bubblewrap executables, and stage tampered bubblewrap bytes in a separate data file before copying them into the executable fixture. Add the required test dependencies.
GitOrigin-RevId: c875c83088731a4933ef1574e8d79d8cecc12f54
## What changed
- Add a configurable `new_worktree` action, bound to `w`, for local sessions with worktree support enabled.
- Create the worktree from the cached project default branch, preferring remote `HEAD` and falling back to conventional `main` or `master` refs without fetching. Preserve the selected subdirectory and source checkout edits.
- Start and bind a blank session in the new worktree, preserving the selected approval reviewer without sending an initial turn.
- Show creation progress, pause conflicting actions, clean up unclaimed clean worktrees, and report retained checkout paths when session startup fails. Clear pending creation state on reconnect.
## Testing
Add coverage for default-branch selection, source checkout preservation, session ownership and approval settings, cleanup, startup failures, reconnect state, and busy-state rendering. Extend Git environment isolation coverage and test unrelated non-UTF-8 refs.
GitOrigin-RevId: 771ddc12d04dbf0d12e77e9c96c8386cf31e67c5
## What changed
- Add `WorktreeManager::create` to create detached, Desktop-compatible worktrees from `HEAD` or an explicit base while preserving the source working-directory path.
- Isolate worktree Git operations from inherited repository selectors, hooks, filesystem monitors, and configured content filters.
- Validate the destination working directory and roll back incomplete worktrees and empty allocation buckets on failure.
## Testing
- Cover layout, base selection, annotated tags, nested working directories, Git environment isolation, filter suppression, source checkout preservation, unsafe symlinks, and creation rollback.
GitOrigin-RevId: bf172c3ff4268dab603d00a1d547485fcd0de368
jif