Refactor screens to MVC architecture with modular widgets

- Extract business logic from screens into dedicated controllers
- Split large screen files into smaller, reusable widget components
- Add controllers for AddSubscriptionScreen and DetailScreen
- Create modular widgets for subscription and detail features
- Improve code organization and maintainability
- Remove duplicated code and improve reusability

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

lib/screens/splash_screen.dart

@@ -1,14 +1,8 @@
 import 'dart:async';
 import 'dart:ui';
 import 'package:flutter/material.dart';
-import 'package:provider/provider.dart';
-import '../providers/app_lock_provider.dart';
-import '../providers/navigation_provider.dart';
 import '../theme/app_colors.dart';
-import '../widgets/glassmorphism_card.dart';
 import '../routes/app_routes.dart';
-import 'app_lock_screen.dart';
-import 'main_screen.dart';
 
 class SplashScreen extends StatefulWidget {
   const SplashScreen({super.key});
@@ -289,7 +283,7 @@ class _SplashScreenState extends State<SplashScreen>
                                                             BlendMode.srcIn,
                                                         shaderCallback:
                                                             (bounds) =>
-                                                                LinearGradient(
+                                                                const LinearGradient(
                                                           colors: AppColors
                                                               .blueGradient,
                                                           begin: