- Add cancellation flag to AniworldLoader with request_cancel/reset_cancel/is_cancelled methods
- Update base_provider.Loader interface with cancellation abstract methods
- Integrate cancellation check in YT-DLP progress hooks
- Add request_download_cancel method to SeriesApp and AnimeService
- Update DownloadService.stop() to request cancellation before shutdown
- Clean up temp files on cancellation
- Add sanitize_folder_name utility for filesystem-safe folder names
- Add sanitized_folder property to Serie entity
- Update SerieList.add() to use sanitized display names for folders
- Add scan_single_series() method for targeted episode scanning
- Enhance add_series endpoint: DB save -> folder create -> targeted scan
- Update response to include missing_episodes and total_missing
- Add comprehensive unit tests for new functionality
- Update API tests with proper mock support
- Add WebSocket shutdown() with client notification and graceful close
- Enhance download service stop() with pending state persistence
- Expand FastAPI lifespan shutdown with proper cleanup sequence
- Add SQLite WAL checkpoint before database close
- Update stop_server.sh to use SIGTERM with timeout fallback
- Configure uvicorn timeout_graceful_shutdown=30s
- Update ARCHITECTURE.md with shutdown documentation
- Add broadcast_scan_started, broadcast_scan_progress, broadcast_scan_completed to WebSocketService
- Inject WebSocketService into AnimeService for real-time scan progress broadcasts
- Add CSS styles for scan progress overlay with spinner, stats, and completion state
- Update app.js to handle scan events and display progress overlay
- Add unit tests for new WebSocket broadcast methods
- All 1022 tests passing
