feat: Add NFO UI features (Task 6)

- 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)

src/server/services/anime_service.py

@@ -884,7 +884,7 @@ class AnimeService:
             AnimeServiceError: If update fails
         """
         from datetime import datetime, timezone
-        
+
         from src.server.database.connection import get_db_session
         from src.server.database.models import AnimeSeries