fix(nfo): add year field to series and create missing NFO files

- Add missing year field when building series list in anime_service
- Add _create_missing_nfo to generate minimal NFO for series without one
- Update perform_nfo_repair_scan to detect and create missing NFOs
- Add semaphore-protected async creation with TMDB rate limiting

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/server/services/anime_service.py

@@ -919,7 +919,8 @@ class AnimeService:
                     name=anime_series.name,
                     site=anime_series.site,
                     folder=anime_series.folder,
-                    episodeDict=episode_dict
+                    episodeDict=episode_dict,
+                    year=anime_series.year
                 )
                 series_list.append(serie)