Audits git worktrees and removes the ones that are safe to delete — merged into the base branch (including squash-merges via `gh`), missing on disk, or explicitly confirmed by the user — then deletes the associated local branches and runs `git worktree prune`. Use when the user asks to clean up worktrees, prune worktrees, list stale worktrees, remove merged worktrees or branches, or reclaim disk space from old checkouts.