Some more cleanup.

Wino.Mail.WinUI/WelcomeWindow.xaml.cs

@@ -3,6 +3,7 @@ using Microsoft.UI.Windowing;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
 using Wino.Core.Domain.Interfaces;
+using Wino.Mail.WinUI.Helpers;
 using Wino.Mail.WinUI.Interfaces;
 using WinUIEx;
 
@@ -11,6 +12,7 @@ namespace Wino.Mail.WinUI;
 public sealed partial class WelcomeWindow : WindowEx
 {
     private bool _allowClose;
+    private bool _isPreparedForClose;
 
     public Frame GetRootFrame() => RootFrame;
 
@@ -25,6 +27,7 @@ public sealed partial class WelcomeWindow : WindowEx
 
         ConfigureWindowChrome();
         AppWindow.Closing += OnAppWindowClosing;
+        Closed += OnWindowClosed;
     }
 
     private void ConfigureWindowChrome()
@@ -55,4 +58,20 @@ public sealed partial class WelcomeWindow : WindowEx
     {
         _allowClose = true;
     }
+
+    public void PrepareForClose()
+    {
+        if (_isPreparedForClose)
+            return;
+
+        _isPreparedForClose = true;
+        WindowCleanupHelper.CleanupFrame(RootFrame);
+    }
+
+    private void OnWindowClosed(object sender, WindowEventArgs e)
+    {
+        Closed -= OnWindowClosed;
+        AppWindow.Closing -= OnAppWindowClosing;
+        PrepareForClose();
+    }
 }