Implement commit sudoku button

lib/main.dart

@@ -7,7 +7,6 @@ import 'package:system_tray/system_tray.dart';
 import 'package:window_manager/window_manager.dart';
 import 'package:audioplayers/audioplayers.dart';
 
-// TODO: Add a "commit sudoku" button to the tray menu
 // TODO: Add an icon to the executable, simply use the existing tray icon
 // TODO: Auto focus new entry field
 
@@ -176,9 +175,22 @@ class _MainPageState extends State<MainPage> with WindowListener {
 
     await _systemTray.initSystemTray(iconPath: iconPath, toolTip: "Journaler");
 
+    await _menu.buildFrom([
+      MenuItemLabel(
+        label: 'Commit Sudoku',
+        onClicked: (menuItem) => windowManager.destroy(),
+      ),
+    ]);
+
+    await _systemTray.setContextMenu(_menu);
+
     _systemTray.registerSystemTrayEventHandler((eventName) {
       debugPrint("System Tray Event: $eventName");
-      _showWindow();
+      if (eventName == kSystemTrayEventClick) {
+        _showWindow();
+      } else if (eventName == kSystemTrayEventRightClick) {
+        _systemTray.popUpContextMenu();
+      }
     });
   }