added saving app placement

CursorLang/App.xaml.cs

@@ -14,6 +14,7 @@ public partial class App : Application
 {
     private ServiceProvider? _services;
     private SingleInstanceGate? _instanceGate;
+    private MainWindowPlacement? _placement;
 
     protected override void OnStartup(StartupEventArgs e)
     {
@@ -36,6 +37,7 @@ public partial class App : Application
 
         _services.GetRequiredService<ThemeService>();
 
+        _placement = _services.GetRequiredService<MainWindowPlacement>();
         MainWindow = _services.GetRequiredService<MainWindow>();
         MainWindow.Show();
 
@@ -68,6 +70,8 @@ public partial class App : Application
             MainWindow.WindowState = WindowState.Normal;
         }
 
+        _placement?.Apply(MainWindow);
+
         MainWindow.Activate();
     }
 
@@ -81,6 +85,8 @@ public partial class App : Application
         services.AddSingleton<ThemeService>();
         services.AddSingleton<IThemeService>(provider => provider.GetRequiredService<ThemeService>());
 
+        services.AddSingleton<MainWindowPlacement>();
+
         services.AddSingleton<ILocalizationService, LocalizationService>();
         services.AddSingleton<IKeyboardLayoutService, KeyboardLayoutService>();
         services.AddSingleton<ILayoutPopupService, LayoutPopupService>();