fix(backend): give track titles room to breathe

Titles were capped at 50 characters and the YouTube provisioner silently cut
them there, which mangles anything with a feature or a remix suffix. Albums
are about to make that far more visible, so the column now holds 200.

backend/Musify.Application/Services/YouTubeTrackProvisioner.cs

@@ -43,7 +43,7 @@ public sealed class YouTubeTrackProvisioner(
         foreach (var artistRef in artistRefs)
             artists.Add(await GetOrCreateArtistAsync(artistRef, cancellationToken));
 
-        var title = Truncate(song.Title, 50);
+        var title = Truncate(song.Title, 200);
         var track = new ExternalTrack
         {
             Title = title,