Squashed replay of the 14 commits on brennanb2025/sta-4343-fix. Twelve of
them predate the branch's own main-merge, so a commit-by-commit rebase
re-conflicts against the worktrees/persistence slice splits every time.
Re-homed by hand where main moved the code:
- persistence.ts -> persistence/loading-store/store.ts (removeWorktreeMeta)
- persistence.test.ts -> persistence-host-partitioned-sessions.test.ts
- ipc/worktrees.test.ts -> worktrees-remove-host-disambiguation.test.ts,
worktrees-removal-recovery.test.ts,
worktrees-preserved-branch-fork-remote.test.ts
Kept main's side where it moved ahead: the folder-workspace
deleteRemoteWorktreeHistory call, and cleanup success toasts no longer
firing from the background-removal path.