Two issues fixed:
1. Worktree directory cleanup used os.Remove() which only removes empty
directories. Changed to os.RemoveAll() to clean up untracked files
left behind by git worktree remove (overlay files, .beads/, etc.)
2. Branch deletion hardcoded mayor/rig but worktrees are created from
.repo.git when using bare repo architecture. Now checks for bare
repo first to match where the branch was created.
Fixes: gt-6ab3cm
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>