fix(ui): restore retail vitals and window interactions

src/AcDream.App/UI/RetailWindowManager.cs

@@ -43,6 +43,12 @@ public sealed class RetailWindowManager : IDisposable
     /// </summary>
     public event Action<RetailWindowHandle>? WindowRegistered;
 
+    /// <summary>
+    /// Internal pre-exposure hook for presentation state that must be correct
+    /// before a newly mounted window's controller receives <c>OnShown</c>.
+    /// </summary>
+    internal event Action<RetailWindowHandle>? WindowRegistering;
+
     /// <summary>
     /// Fires when a window is REMOVED from the registry (<see cref="Unregister"/>),
     /// after teardown (<c>NotifyClosed</c>/<c>DisposeController</c>) but before the
@@ -99,6 +105,7 @@ public sealed class RetailWindowManager : IDisposable
             authoredGeometryRevision);
         _byName.Add(name, handle);
         _byFrame.Add(outerFrame, handle);
+        WindowRegistering?.Invoke(handle);
         handle.NotifyInitialState();
         WindowRegistered?.Invoke(handle);
         return handle;
@@ -258,6 +265,7 @@ public sealed class RetailWindowManager : IDisposable
             _defaultInputs.Remove(handle);
             handle.NotifyClosed();
             handle.DisposeController();
+            WindowUnregistered?.Invoke(handle);
         }
     }