- 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
- Remove db_session parameter from SeriesApp, SerieList, SerieScanner
- Move all database operations to AnimeService (service layer)
- Add add_series_to_db, contains_in_db methods to AnimeService
- Update sync_series_from_data_files to use inline DB operations
- Remove obsolete test classes for removed DB methods
- Fix pylint issues: add broad-except comments, fix line lengths
- Core layer (src/core/) now has zero database imports
722 unit tests pass