## What changed
- Add the `codex-worktree` crate for resolving managed worktree settings from
the existing `[desktop]` configuration.
- Default the worktree root to `$CODEX_HOME/worktrees`, automatic cleanup to
enabled, and retained worktrees to 15.
- Validate configured roots, cleanup flags, and retention counts before
exposing the effective settings.
## Testing
- Cover defaults, configured values, and invalid root and retention settings.
GitOrigin-RevId: 1b279c62ef41e3c8eb540ce9beaf0f6cd96d903f
