Add track publication, album types, optional track pictures and batch upload URLs

Tracks
- Track.IsPublished (migration marks existing tracks as published). New
  tracks are created unpublished.
- PUT /tracks/{id}/published and PUT /tracks/published change the flag;
  publishing requires completed audio processing (the batch endpoint
  reports skipped tracks).
- An unpublished track is only visible to its owner. A WherePublished /
  VisibleTo filter is applied to search, genres, listening history, last
  listened, likes, mixes, album and playlist contents and counts, recently
  listened albums, public user tracks, track details and stream tickets.
- isPublished is part of the track responses, GET /tracks/users/{userId}
  accepts a published filter and status-counts reports published and
  unpublished totals.
- CreateTrackRequest.pictureIntentId is optional: without it the track
  uses the album cover or the preset picture and no picture processing
  runs. CreateTrackResourcesEvent carries nullable picture fields, so
  queues must be drained before deploying.
- POST /tracks/upload-urls accepts an audios list and one optional picture
  shared by all of them, and returns an intent per file. The upload intent
  limits are raised so a batch fits.

Albums
- AlbumType (Album, EP, Single) on create, update and responses.
- CreateAlbumRequest.trackIds creates the album and links the tracks in a
  single save.

backend/Core/Musify.Application/PlayLists/AddAlbumToPlayList.cs

@@ -34,7 +34,7 @@ namespace Musify.Application.PlayLists
 
             var albumTrackIds = await database.AlbumHasTracks
                 .AsNoTracking()
-                .Where(albumTrack => albumTrack.AlbumId == request.AlbumId && albumTrack.Track.LifeCycleStatus == LifeCycleStatus.Active)
+                .Where(albumTrack => albumTrack.AlbumId == request.AlbumId && albumTrack.Track.LifeCycleStatus == LifeCycleStatus.Active && albumTrack.Track.IsPublished)
                 .OrderBy(albumTrack => albumTrack.TrackNumber)
                 .Select(albumTrack => albumTrack.TrackId)
                 .ToListAsync(cancellationToken);

backend/Core/Musify.Application/PlayLists/AddTracksToPlayList.cs

@@ -27,7 +27,7 @@ namespace Musify.Application.PlayLists
 
             var existingIds = await database.Tracks
                 .AsNoTracking()
-                .Where(track => requestedIds.Contains(track.Id) && track.LifeCycleStatus == LifeCycleStatus.Active)
+                .Where(track => requestedIds.Contains(track.Id) && track.LifeCycleStatus == LifeCycleStatus.Active && track.IsPublished)
                 .Select(track => track.Id)
                 .ToListAsync(cancellationToken);
 

backend/Core/Musify.Application/PlayLists/GetPlayListTracks.cs

@@ -31,7 +31,7 @@ namespace Musify.Application.PlayLists
 
             return await database.PlayListHasTracks
                 .AsNoTracking()
-                .Where(playListTrack => playListTrack.PlayListId == request.PlayListId && playListTrack.Track.LifeCycleStatus == LifeCycleStatus.Active)
+                .Where(playListTrack => playListTrack.PlayListId == request.PlayListId && playListTrack.Track.LifeCycleStatus == LifeCycleStatus.Active && playListTrack.Track.IsPublished)
                 .OrderBy(playListTrack => playListTrack.Position)
                 .ThenBy(playListTrack => playListTrack.Id)
                 .Select(playListTrack => playListTrack.Track)

backend/Core/Musify.Application/PlayLists/Responses/PlayListProjections.cs

@@ -25,14 +25,15 @@ namespace Musify.Application.PlayLists.Responses
                 playList.CreatedAt,
                 playList.UpdatedAt,
                 playList.PlayListTracks
+                    .Where(playListTrack => playListTrack.Track.LifeCycleStatus == LifeCycleStatus.Active && playListTrack.Track.IsPublished)
                     .OrderBy(playListTrack => playListTrack.Position)
                     .Take(CoverTrackCount)
                     .Select(playListTrack => playListTrack.TrackId)
                     .ToList(),
                 playList.OwnerUserId,
-                playList.PlayListTracks.Count(playListTrack => playListTrack.Track.LifeCycleStatus == LifeCycleStatus.Active),
+                playList.PlayListTracks.Count(playListTrack => playListTrack.Track.LifeCycleStatus == LifeCycleStatus.Active && playListTrack.Track.IsPublished),
                 playList.PlayListTracks
-                    .Where(playListTrack => playListTrack.Track.LifeCycleStatus == LifeCycleStatus.Active)
+                    .Where(playListTrack => playListTrack.Track.LifeCycleStatus == LifeCycleStatus.Active && playListTrack.Track.IsPublished)
                     .Sum(playListTrack => playListTrack.Track.DurationSeconds)));
     }
 }