fix: route all _isMinimized mutations through SetMinimized so spacer stays in sync

Expand, ToggleMinimized, and Close now share one guarded mutator that fires
OnMinimized and renders. Fixed prerender branch left as a direct assignment.

DeepDrftPublic.Client/Controls/AudioPlayerBar/AudioPlayerBar.razor.cs

@@ -115,14 +115,23 @@ public partial class AudioPlayerBar : ComponentBase, IAsyncDisposable
         }
     }
 
-    private async Task Expand()
+    private async Task Expand() => await SetMinimized(false);
+
+    /// <summary>
+    /// The single assignment site for <see cref="_isMinimized"/>. Guards no-op transitions,
+    /// fires <see cref="OnMinimized"/> so MainLayout's spacer class stays in sync, and renders
+    /// so OnAfterRenderAsync re-evaluates the ResizeObserver on every transition path.
+    /// The <c>Fixed</c> branch in OnParametersSet intentionally bypasses this — it is a
+    /// prerender/parameter pass, not a user-driven transition, and the embed host has no spacer.
+    /// </summary>
+    private async Task SetMinimized(bool value)
     {
-        if (_isMinimized)
-        {
-            _isMinimized = false;
+        if (_isMinimized == value) return;
+
+        _isMinimized = value;
+        if (OnMinimized.HasDelegate) await OnMinimized.InvokeAsync(value);
         StateHasChanged();
     }
-    }
 
     private async Task TogglePlayPause()
     {
@@ -176,12 +185,7 @@ public partial class AudioPlayerBar : ComponentBase, IAsyncDisposable
         PlayerService?.ClearError();
     }
 
-    private async Task ToggleMinimized()
-    {
-        _isMinimized = !_isMinimized;
-        if (OnMinimized.HasDelegate) await OnMinimized.InvokeAsync(_isMinimized);
-        StateHasChanged();
-    }
+    private async Task ToggleMinimized() => await SetMinimized(!_isMinimized);
 
     private async Task Close()
     {
@@ -190,11 +194,7 @@ public partial class AudioPlayerBar : ComponentBase, IAsyncDisposable
             await PlayerService.Unload();
         }
 
-        if (!_isMinimized)
-        {
-            _isMinimized = true;
-            StateHasChanged();
-        }
+        await SetMinimized(true);
     }
     
     public async ValueTask DisposeAsync()