Use the database as the authoritative source for missing-episode lists so
that episodes marked is_downloaded=True are never shown as missing, even
when the in-memory state is stale.
Key changes:
- EpisodeService.get_by_series() gains only_missing flag
- AnimeService uses DB-backed episodeDict and preserves downloaded episodes
during sync, skipping them when adding/removing missing episodes
- DownloadService broadcasts series_updated after marking an episode downloaded
so the frontend reflects the change immediately
- Frontend filters out series with zero missing episodes client-side and
fixes renderSeries to respect the active filter
- Unit tests updated to assert the broadcast is sent
- Implement sync_single_series_after_scan to persist scanned series to database
- Enhanced _broadcast_series_updated to include full NFO metadata (nfo_created_at, nfo_updated_at, tmdb_id, tvdb_id)
- Add immediate episode scanning in add_series endpoint when background loader isn't running
- Implement updateSingleSeries in frontend to handle series_updated WebSocket events
- Add SERIES_UPDATED event constant to WebSocket event definitions
- Update background loader to use sync_single_series_after_scan method
- Simplified background loader initialization in FastAPI app
- Add comprehensive tests for series update WebSocket payload and episode counting logic
- Import reorganization: move get_background_loader_service to dependencies module
- Add SERIES_LOADING_UPDATE WebSocket event
- Update series cards to display loading indicators
- Add real-time status updates via WebSocket
- Include progress tracking (episodes, NFO, logo, images)
- Add CSS styling for loading states
- Implement updateSeriesLoadingStatus function
- Extended AnimeSummary model with NFO fields (has_nfo, nfo_created_at, nfo_updated_at, tmdb_id, tvdb_id)
- Updated list_anime endpoint to fetch and return NFO data from database
- Added NFO status badges to series cards (green=exists, gray=missing)
- Created nfo-manager.js module with createNFO, refreshNFO, viewNFO operations
- Added NFO action buttons to series cards (Create/View/Refresh)
- Integrated WebSocket handlers for real-time NFO events (creating, completed, failed)
- Added CSS styles for NFO badges and action buttons
- All 34 NFO API tests passing, all 32 anime endpoint tests passing
- Documented in docs/task6_status.md (90% complete, NFO status page deferred)
