feat: initialize WinUI 3 WebView migration

App.xaml.cs

@@ -0,0 +1,20 @@
+namespace MBN_STOCK_WEBVIEW;
+
+/// <summary>
+/// Application entry point for the packaged WinUI 3 desktop app.
+/// </summary>
+public partial class App : Application
+{
+    private Window? _window;
+
+    public App()
+    {
+        InitializeComponent();
+    }
+
+    protected override void OnLaunched(LaunchActivatedEventArgs args)
+    {
+        _window = new MainWindow();
+        _window.Activate();
+    }
+}