Expand test coverage: ~188 new tests across 6 critical files
- Fix failing test_authenticated_request_succeeds (dependency override)
- Expand test_anime_service.py (+35 tests: status events, DB, broadcasts)
- Create test_queue_repository.py (27 tests: CRUD, model conversion)
- Expand test_enhanced_provider.py (+24 tests: fetch, download, redirect)
- Expand test_serie_scanner.py (+25 tests: events, year extract, mp4 scan)
- Create test_database_connection.py (38 tests: sessions, transactions)
- Expand test_anime_endpoints.py (+39 tests: status, search, loading)
- Clean up docs/instructions.md TODO list