Basic window handling.

Wino.Core.UWP/Services/AppShellService.cs

@@ -0,0 +1,19 @@
+#if NET8_0
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+#else
+using Windows.UI.Xaml;
+#endif
+
+namespace Wino.Core.WinUI.Services
+{
+    public interface IAppShellService
+    {
+        Window AppWindow { get; set; }
+    }
+
+    public class AppShellService : IAppShellService
+    {
+        public Window AppWindow { get; set; }
+    }
+}