Make release Medium writable via upload + meta-edit; resolve detail-page track by releaseId not album title

DeepDrftAPI/Services/UnifiedTrackService.cs

@@ -53,6 +53,7 @@ public class UnifiedTrackService
         long createdByUserId,
         string? originalFileName,
         ReleaseType releaseType,
+        ReleaseMedium medium,
         int trackNumber,
         CancellationToken ct)
     {
@@ -81,9 +82,15 @@ public class UnifiedTrackService
                 Genre = genre,
                 ReleaseDate = releaseDate,
                 ReleaseType = releaseType,
+                Medium = medium,
                 CreatedByUserId = createdByUserId,
             };
 
+            // Medium (like every other field in releaseData) applies only when this upload CREATES the
+            // release. FindOrCreateRelease returns an existing (title, artist) row untouched — the first
+            // upload's medium is authoritative. Do NOT "fix" this to overwrite the stored medium on a
+            // subsequent track add: medium is a release-level property, changed only via the edit path
+            // (PUT api/track/meta), never silently flipped by adding a track to an existing release.
             var releaseResult = await _sqlTrackService.FindOrCreateRelease(album, artist, releaseData, ct);
             if (!releaseResult.Success || releaseResult.Value is null)
             {