feat: add home and profile screens

lib/profile/profile_screen.dart

@@ -0,0 +1,24 @@
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:phone_login/auth/auth_state.dart';
+
+class ProfileScreen extends StatelessWidget {
+  const ProfileScreen({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final authState = Provider.of<AuthState>(context, listen: false);
+
+    return Scaffold(
+      appBar: AppBar(title: const Text('Profile')),
+      body: Center(
+        child: ElevatedButton(
+          onPressed: () {
+            authState.toggleLogin();
+          },
+          child: const Text('Logout'),
+        ),
+      ),
+    );
+  }
+}