fix(dock): ensure exception-safe reentrancy guard and symmetrical event cleanup

src/Editor/Ghost.Editor/View/Controls/DockLayout.Rendering.cs

@@ -110,6 +110,8 @@ public sealed partial class DockLayout
     {
         if (_isSyncingSizes) return;
 
+        try
+        {
             bool isHorizontal = groupNode.Orientation == Orientation.Horizontal;
             bool changed = false;
 
@@ -152,8 +154,8 @@ public sealed partial class DockLayout
                     }
                 }
             }
-
-        if (changed)
+        }
+        finally
         {
             _isSyncingSizes = false;
         }

src/Editor/Ghost.Editor/View/Windows/EngineEditorWindow.xaml.cs

@@ -42,6 +42,13 @@ internal sealed partial class EngineEditorWindow : WindowEx
         this.CenterOnScreen();
 
         InitializeDockLayout();
+        
+        this.Unloaded += OnUnloaded;
+    }
+
+    private void OnUnloaded(object sender, RoutedEventArgs e)
+    {
+        PART_DockLayout.TabTornOff -= OnTabTornOff;
     }
 
     private void InitializeDockLayout()
@@ -68,7 +75,12 @@ internal sealed partial class EngineEditorWindow : WindowEx
         root.AddChild(rightGroup);
 
         PART_DockLayout.Root = root;
-        PART_DockLayout.TabTornOff += (s, e) => App.CreateAndShowDockWindow(e.TabContent);
+        PART_DockLayout.TabTornOff += OnTabTornOff;
+    }
+
+    private void OnTabTornOff(object? sender, TabTornOffEventArgs e)
+    {
+        App.CreateAndShowDockWindow(e.TabContent);
     }
 
     private void MainGrid_Loaded(object sender, Microsoft.UI.Xaml.RoutedEventArgs e)