Fixing the leak in calendar mmode.

Wino.Mail.WinUI/Views/Calendar/CalendarPage.xaml.cs

@@ -52,6 +52,12 @@ public sealed partial class CalendarPage : CalendarPageAbstract, ITitleBarSearch
         base.OnNavigatingFrom(e);
     }
 
+    public override void PrepareForClose()
+    {
+        DetachNavigationLifetimeEvents();
+        base.PrepareForClose();
+    }
+
     protected override void OnNavigatedTo(NavigationEventArgs e)
     {
         base.OnNavigatedTo(e);

Wino.Mail.WinUI/Views/WinoAppShell.xaml.cs

@@ -168,6 +168,8 @@ public sealed partial class WinoAppShell : Views.Abstract.WinoAppShellAbstract,
         {
             ViewModel.StatePersistenceService.IsEventDetailsVisible = false;
             ViewModel.CalendarClient.Deactivate();
+            WindowCleanupHelper.CleanupFrame(InnerShellFrame);
+            GC.Collect();
         }
         else if (_activeMode == WinoApplicationMode.Contacts)
         {