feat: normalize release-cardinal fields out of track into a Release entity (Phase 8 §8.0)

DeepDrftAPI/Services/UnifiedTrackService.cs

@@ -65,11 +65,43 @@ public class UnifiedTrackService
             return ResultContainer<TrackDto>.CreateFailResult("Failed to process and store WAV.");
         }
 
-        unpersisted.CreatedByUserId = createdByUserId;
-        unpersisted.ReleaseType = releaseType;
         unpersisted.TrackNumber = trackNumber;
 
-        var saveResult = await _sqlTrackService.Create(TrackConverter.Convert(unpersisted));
+        // Resolve the release FK before persisting the track. An upload with an album lands on the
+        // shared release (created on first sighting); an upload without one stays a loose track with
+        // a null ReleaseId. Release-cardinal metadata (artist/genre/releaseDate/type/uploader) rides
+        // on the release, not the track.
+        long? releaseId = null;
+        if (!string.IsNullOrWhiteSpace(album))
+        {
+            var releaseData = new ReleaseDto
+            {
+                Title = album,
+                Artist = artist,
+                Genre = genre,
+                ReleaseDate = releaseDate,
+                ReleaseType = releaseType,
+                CreatedByUserId = createdByUserId,
+            };
+
+            var releaseResult = await _sqlTrackService.FindOrCreateRelease(album, artist, releaseData, ct);
+            if (!releaseResult.Success || releaseResult.Value is null)
+            {
+                var error = releaseResult.Messages.FirstOrDefault()?.Message ?? "Unknown error";
+                _logger.LogError(
+                    "Track persisted to vault but release resolution failed. Orphaned entry: {EntryKey}. Error: {Error}",
+                    unpersisted.EntryKey, error);
+                return ResultContainer<TrackDto>.CreateFailResult($"Track was uploaded but could not be saved: {error}");
+            }
+
+            releaseId = releaseResult.Value.Id;
+        }
+
+        var trackDto = TrackConverter.Convert(unpersisted);
+        trackDto.ReleaseId = releaseId;
+        trackDto.Release = null; // FK already resolved; Create must not re-resolve a detached graph.
+
+        var saveResult = await _sqlTrackService.Create(trackDto);
         if (!saveResult.Success || saveResult.Value is null)
         {
             // Vault write succeeded, SQL persist failed — audio is orphaned in the tracks vault