fix(cms): fix grid cell vertical stacking; add per-track regenerate buttons

MixBrowser WaveformCell: wrap icon+button in MudStack Row. SessionBrowser
HeroCell: split into two SpecialActionColumns (thumb + button). AlbumBrowser
track table: always show regenerate button for Profile and High-res.

DeepDrftManager/Components/Pages/Tracks/CmsSessionBrowser.razor

@@ -85,13 +85,16 @@ else
 
     protected override void OnInitialized()
     {
-        _specialColumns = new[] { new SpecialActionColumn("Hero", HeroCell) };
+        _specialColumns = new[]
+        {
+            new SpecialActionColumn("Hero", HeroThumbCell),
+            new SpecialActionColumn("", HeroButtonCell),
+        };
         base.OnInitialized();
     }
 
-    // Per-row cell for the dedicated "Hero" column: thumbnail preview plus set/replace upload button with
-    // progress. Recovers the typed SessionRow via RowFor; skips rendering for a release not on the page.
-    private RenderFragment<ReleaseDto> HeroCell => release =>@<text>
+    // Per-row cell for the "Hero" thumbnail column: just the image preview div.
+    private RenderFragment<ReleaseDto> HeroThumbCell => release =>@<text>
         @{ var row = RowFor(release); }
         @if (row is not null)
         {
@@ -103,6 +106,14 @@ else
             {
                 <div class="cms-album-thumb cms-album-thumb--fallback"></div>
             }
+        }
+    </text>;
+
+    // Per-row cell for the "Hero Image" upload button column: set/replace upload button with progress.
+    private RenderFragment<ReleaseDto> HeroButtonCell => release =>@<text>
+        @{ var row = RowFor(release); }
+        @if (row is not null)
+        {
             <MudFileUpload T="IBrowserFile"
                            Accept="image/*"
                            FilesChanged="@(file => UploadHeroAsync(row, file))"