feat: Initialize Flutter app with authentication and scheduling features

- Removed TypeScript configuration file (tsconfig.json).
- Added Flutter plugin dependencies for secure storage.
- Implemented main application structure with routing for login, profile, and schedule screens.
- Developed LoginScreen with authentication logic and user feedback.
- Created ProfileScreen to display user profile information and logout functionality.
- Built ScheduleScreen to show weekly work schedule with navigation controls.
- Integrated AuthService for handling authentication, token storage, and API interactions.
- Updated pubspec.yaml with necessary dependencies for the Flutter project.

lib/main.dart

@@ -0,0 +1,33 @@
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+
+import 'screens/login_screen.dart';
+import 'screens/profile_screen.dart';
+import 'screens/schedule_screen.dart';
+import 'services/auth_service.dart';
+
+void main() {
+  runApp(MyApp());
+}
+
+class MyApp extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return ChangeNotifierProvider(
+      create: (_) => AuthService(),
+      child: MaterialApp(
+        title: 'ISO Flutter',
+        theme: ThemeData.dark().copyWith(
+          primaryColor: Color(0xFFA24BFA),
+          scaffoldBackgroundColor: Color(0xFF0c0a0a),
+        ),
+        initialRoute: '/',
+        routes: {
+          '/': (context) => LoginScreen(),
+          '/profile': (context) => ProfileScreen(),
+          '/schedule': (context) => ScheduleScreen(),
+        },
+      ),
+    );
+  }
+}