- Fix: default None output now always treated as directory (timestamped filename)
- Fix: test_auth.py corrupted with line number prefixes cleaned up via regex
- Add: 20 tests for download.py covering path resolution, export, auth, CLI, full flow
- test_login_full_flow: Set-Cookie uses list format for httpx compatibility
- All 47 tests passing (27 auth + 20 download)
