Some issues with changing the app mode and notifications have been fixed.

Wino.Mail.WinUI/Dispatcher.cs

@@ -8,12 +8,38 @@ namespace Wino.Mail.WinUI;
 
 public class WinUIDispatcher : IDispatcher
 {
-    private readonly DispatcherQueue _coreDispatcher;
+    private DispatcherQueue? _coreDispatcher;
+
+    public WinUIDispatcher()
+    {
+    }
 
     public WinUIDispatcher(DispatcherQueue coreDispatcher)
     {
         _coreDispatcher = coreDispatcher;
     }
 
-    public Task ExecuteOnUIThread(Action action) => _coreDispatcher.EnqueueAsync(action, DispatcherQueuePriority.Normal);
+    public bool HasThreadAccess => _coreDispatcher?.HasThreadAccess == true;
+
+    public void Initialize(DispatcherQueue coreDispatcher)
+    {
+        _coreDispatcher ??= coreDispatcher ?? throw new ArgumentNullException(nameof(coreDispatcher));
+    }
+
+    public Task ExecuteOnUIThread(Action action)
+    {
+        if (action == null)
+            throw new ArgumentNullException(nameof(action));
+
+        if (_coreDispatcher == null)
+            throw new InvalidOperationException("UI dispatcher is not initialized.");
+
+        if (_coreDispatcher.HasThreadAccess)
+        {
+            action();
+            return Task.CompletedTask;
+        }
+
+        return _coreDispatcher.EnqueueAsync(action, DispatcherQueuePriority.Normal);
+    }
 }