In git worktrees, .git is a file (not a directory) containing a gitdir
pointer. The -d test fails for worktree checkouts, causing project
detection to fall through to the "global" fallback. Changing to -e
(exists) handles both regular repos and worktrees correctly.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>