If you run multi-session agent fleets, you know this smell: git worktree list scrolling past checkouts nobody owns anymore. A session died, its worktree leaked, and now there are six stale branches with names like fix-thing-3 that nobody dares to delete. Multiply by every fleet run and you get a repo full of ghost worktrees. Ben Newton's worktree claim guard (a session-fleet Mod) proved this is a real problem class: sessions racing over the same worktrees. Guards solve it at creati...