feat: add genre, rating, and avoid-repeats trailer filters

Trailer selection now supports three optional filters:
- Genre match: prefer trailers whose fake-movie genre overlaps with the
  feature being played (requires TMDB genres in NFO)
- Age rating ceiling: exclude trailers rated higher than the feature
  (requires TMDB certification in NFO)
- Avoid repeats: cycle through all trailers before replaying any;
  resets per-user once the pool is exhausted

Genre and certification are fetched from TMDB at download time via a
single /movie/{id}?append_to_response=release_dates call and written
into the fake-movie NFO as <genre> and <mpaa> tags. All filters fall
back to the full unfiltered pool when no match is found.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Jellyfin.Plugin.CinemaTrailers4Jellyfins/ScheduledTasks/DownloadTrailersTask.cs

@@ -168,7 +168,10 @@ namespace Jellyfin.Plugin.CinemaTrailers4Jellyfins.ScheduledTasks
                     continue;
                 }
 
-                _fakeMovieService.WriteNfo(paths.NfoPath, movie.Title, movie.Year);
+                var metadata = await _tmdbService.GetMovieMetadataAsync(
+                    movie.Id.ToString(), config.TmdbApiKey, cancellationToken).ConfigureAwait(false);
+
+                _fakeMovieService.WriteNfo(paths.NfoPath, movie.Title, movie.Year, metadata.Genres, metadata.Certification);
 
                 downloaded++;
                 _logger.LogInformation(