refactor entire frontend

frontend/lib/app_menu.dart

@@ -0,0 +1,29 @@
+import 'package:flutter/material.dart';
+import 'chat_list_screen.dart';
+
+class AppMenu extends StatelessWidget {
+  const AppMenu({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(title: const Text('Menu')),
+      body: ListView(
+        children: <Widget>[
+          ListTile(
+            title: const Text('Chats'),
+            onTap: () {
+              Navigator.push(
+                context,
+                MaterialPageRoute(
+                  builder: (context) => const ChatListScreen(),
+                ),
+              );
+            },
+          ),
+          // Add other settings options here
+        ],
+      ),
+    );
+  }
+}