Expand description
cwd-based scope discovery for gw.
Determines which worktrees a gw command should act on based on the invocation directory. Two cases:
- cwd inside a git worktree → return that worktree’s family (main repo + all linked worktrees).
- cwd outside any repo → walk down (depth ≤ 4, skipping dotdirs and common build dirs) and gather every distinct repo family found.