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

DeepDrftManager/Components/Pages/Tracks/TrackEdit.razor

@@ -210,6 +210,7 @@
                 releaseDate,
                 string.IsNullOrEmpty(_form.ImagePath) ? "" : _form.ImagePath,
                 _form.ReleaseType,
+                _form.Medium,
                 _form.TrackNumber);
             if (updated.Success)
             {
@@ -298,8 +299,8 @@
         public DateTime? ReleaseDate { get; set; }
         public ReleaseType ReleaseType { get; set; } = ReleaseType.Single;
 
-        // Drives ReleaseType visibility via MediumFields. NOTE: not persisted — PUT api/track/meta has
-        // no medium field, so a medium change on edit is form-shape only until the API grows one.
+        // Drives ReleaseType visibility via MediumFields and is persisted on save (PUT api/track/meta
+        // carries Medium). A non-Cut medium resets ReleaseType to its default server-side.
         public ReleaseMedium Medium { get; set; } = ReleaseMedium.Cut;
         public int TrackNumber { get; set; } = 1;