fix(analysis): handle delete return value, resolve commit once, fix test ordering

- Handle Boolean return from tempDir.delete() with deleteOnExit fallback
- Resolve commit hash once before shortHash and createWorktree calls
  to prevent non-deterministic results from mutable refs
- Move readText() after waitFor() in test helpers to prevent blocking

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>