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/app_lock_screen.dart

@@ -38,7 +38,7 @@ class AppLockScreen extends StatelessWidget {
               onPressed: () async {
                 final appLock = context.read<AppLockProvider>();
                 final success = await appLock.authenticate();
-                if (!success) {
+                if (!success && context.mounted) {
                   ScaffoldMessenger.of(context).showSnackBar(
                     const SnackBar(
                       content: Text('인증에 실패했습니다. 다시 시도해주세요.'),

lib/screens/category_management_screen.dart

@@ -1,7 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 import '../providers/category_provider.dart';
-import '../models/category_model.dart';
 
 class CategoryManagementScreen extends StatefulWidget {
   const CategoryManagementScreen({super.key});

lib/screens/main_screen.dart

@@ -1,7 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:provider/provider.dart';
-import '../providers/subscription_provider.dart';
 import '../providers/app_lock_provider.dart';
 import '../providers/navigation_provider.dart';
 import '../theme/app_colors.dart';
@@ -13,7 +12,6 @@ import 'sms_scan_screen.dart';
 import '../utils/animation_controller_helper.dart';
 import '../widgets/floating_navigation_bar.dart';
 import '../widgets/glassmorphic_scaffold.dart';
-import '../widgets/glassmorphic_app_bar.dart';
 import '../widgets/home_content.dart';
 
 class MainScreen extends StatefulWidget {
@@ -33,7 +31,6 @@ class _MainScreenState extends State<MainScreen>
   late AnimationController _waveController;
   late ScrollController _scrollController;
   late FloatingNavBarScrollController _navBarScrollController;
-  bool _isNavBarVisible = true;
   
   // 화면 목록
   late final List<Widget> _screens;
@@ -67,8 +64,8 @@ class _MainScreenState extends State<MainScreen>
     
     _navBarScrollController = FloatingNavBarScrollController(
       scrollController: _scrollController,
-      onHide: () => setState(() => _isNavBarVisible = false),
-      onShow: () => setState(() => _isNavBarVisible = true),
+      onHide: () {},
+      onShow: () {},
     );
 
     // 화면 목록 초기화
@@ -162,17 +159,18 @@ class _MainScreenState extends State<MainScreen>
       // 구독이 성공적으로 추가된 경우
       if (result == true) {
         // 상단에 스낵바 표시
+        if (!context.mounted) return;
         ScaffoldMessenger.of(context).showSnackBar(
           SnackBar(
-            content: Row(
+            content: const Row(
               children: [
-                const Icon(
+                Icon(
                   Icons.check_circle,
                   color: Colors.white,
                   size: 20,
                 ),
-                const SizedBox(width: 12),
-                const Text(
+                SizedBox(width: 12),
+                Text(
                   '구독이 추가되었습니다',
                   style: TextStyle(
                     fontSize: 16,

lib/screens/settings_screen.dart

@@ -1,24 +1,13 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/foundation.dart' show kIsWeb;
 import 'package:provider/provider.dart';
-import '../providers/app_lock_provider.dart';
 import '../providers/notification_provider.dart';
-import '../providers/subscription_provider.dart';
-import '../providers/navigation_provider.dart';
-import 'package:share_plus/share_plus.dart';
-import 'package:path_provider/path_provider.dart';
 import 'dart:io';
-import 'package:path/path.dart' as path;
 import '../services/notification_service.dart';
-import '../screens/sms_scan_screen.dart';
 import 'package:url_launcher/url_launcher.dart';
 import '../providers/theme_provider.dart';
 import '../theme/adaptive_theme.dart';
-import '../widgets/glassmorphic_scaffold.dart';
-import '../widgets/glassmorphic_app_bar.dart';
 import '../widgets/glassmorphism_card.dart';
-import '../widgets/app_navigator.dart';
-import '../theme/app_colors.dart';
 
 class SettingsScreen extends StatelessWidget {
   const SettingsScreen({super.key});
@@ -76,65 +65,7 @@ class SettingsScreen extends StatelessWidget {
     );
   }
 
-  Future<void> _backupData(BuildContext context) async {
-    try {
-      final provider = context.read<SubscriptionProvider>();
-      final subscriptions = provider.subscriptions;
 
-      // 임시 디렉토리에 백업 파일 생성
-      final tempDir = await getTemporaryDirectory();
-      final backupFile =
-          File(path.join(tempDir.path, 'submanager_backup.json'));
-
-      // 구독 데이터를 JSON 형식으로 저장
-      final jsonData = subscriptions
-          .map((sub) => {
-                'id': sub.id,
-                'serviceName': sub.serviceName,
-                'monthlyCost': sub.monthlyCost,
-                'billingCycle': sub.billingCycle,
-                'nextBillingDate': sub.nextBillingDate.toIso8601String(),
-                'isAutoDetected': sub.isAutoDetected,
-                'repeatCount': sub.repeatCount,
-                'lastPaymentDate': sub.lastPaymentDate?.toIso8601String(),
-              })
-          .toList();
-
-      await backupFile.writeAsString(jsonData.toString());
-
-      // 파일 공유
-      await Share.shareXFiles(
-        [XFile(backupFile.path)],
-        text: 'SubManager 백업 파일',
-      );
-
-      if (context.mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(content: Text('백업 파일이 생성되었습니다')),
-        );
-      }
-    } catch (e) {
-      if (context.mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
-          SnackBar(content: Text('백업 중 오류가 발생했습니다: $e')),
-        );
-      }
-    }
-  }
-
-  // SMS 스캔 화면으로 이동
-  void _navigateToSmsScan(BuildContext context) async {
-    final added = await Navigator.push<bool>(
-      context,
-      MaterialPageRoute(builder: (context) => const SmsScanScreen()),
-    );
-
-    if (added == true && context.mounted) {
-      ScaffoldMessenger.of(context).showSnackBar(
-        const SnackBar(content: Text('구독이 성공적으로 추가되었습니다')),
-      );
-    }
-  }
 
   @override
   Widget build(BuildContext context) {
@@ -455,10 +386,10 @@ class SettingsScreen extends StatelessWidget {
           ),
 
           // 데이터 관리
-          GlassmorphismCard(
+          const GlassmorphismCard(
             margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
             padding: const EdgeInsets.all(8),
-            child: Column(
+            child: const Column(
               children: [
                 // 데이터 백업 기능 비활성화
                 // ListTile(

lib/screens/sms_scan_screen.dart

@@ -7,11 +7,8 @@ import '../models/subscription.dart';
 import '../models/subscription_model.dart';
 import '../services/subscription_url_matcher.dart';
 import 'package:intl/intl.dart'; // NumberFormat을 사용하기 위한 import 추가
-import '../widgets/glassmorphic_scaffold.dart';
-import '../widgets/glassmorphic_app_bar.dart';
 import '../widgets/glassmorphism_card.dart';
 import '../widgets/themed_text.dart';
-import '../theme/app_colors.dart';
 
 class SmsScanScreen extends StatefulWidget {
   const SmsScanScreen({super.key});

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: