Initial commit: SubManager Flutter App

주요 구현 완료 기능:
- 구독 관리 (추가/편집/삭제/카테고리 분류)
- 이벤트 할인 시스템 (기본값 자동 설정)
- SMS 자동 스캔 및 구독 정보 추출
- 알림 시스템 (타임존 처리 안정화)
- 환율 변환 지원 (KRW/USD)
- 반응형 UI 및 애니메이션
- 다국어 지원 (한국어/영어)

버그 수정:
- NotificationService tz.local 초기화 오류 해결
- MainScreenSummaryCard 레이아웃 오버플로우 수정
- 구독 추가 시 LateInitializationError 완전 해결

🤖 Generated with Claude Code

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

lib/providers/app_lock_provider.dart

@@ -0,0 +1,171 @@
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:local_auth/local_auth.dart';
+import 'package:flutter_secure_storage/flutter_secure_storage.dart';
+import '../services/notification_service.dart';
+import '../providers/subscription_provider.dart';
+import 'package:hive_flutter/hive_flutter.dart';
+import 'package:flutter/foundation.dart' show kIsWeb;
+
+class AppLockProvider extends ChangeNotifier {
+  final Box<bool> _appLockBox;
+  final LocalAuthentication _localAuth = LocalAuthentication();
+  final FlutterSecureStorage _secureStorage = const FlutterSecureStorage();
+  static const String _isEnabledKey = 'app_lock_enabled';
+
+  bool _isEnabled = false;
+  bool _isLocked = false;
+  bool _isBiometricEnabled = false;
+  bool _isBiometricAvailable = false;
+
+  AppLockProvider(this._appLockBox) {
+    _init();
+  }
+
+  bool get isEnabled => _isEnabled;
+  bool get isLocked => _isLocked;
+  bool get isBiometricEnabled => _isBiometricEnabled;
+  bool get isBiometricAvailable => _isBiometricAvailable;
+
+  Future<void> _init() async {
+    if (!kIsWeb) {
+      _isBiometricAvailable = await _localAuth.canCheckBiometrics;
+    } else {
+      _isBiometricAvailable = false;
+    }
+    _isLocked = _appLockBox.get('isLocked', defaultValue: false) ?? false;
+    await _loadState();
+    notifyListeners();
+  }
+
+  Future<void> _loadState() async {
+    final value = await _secureStorage.read(key: _isEnabledKey);
+    _isEnabled = value == 'true';
+    _isLocked = _appLockBox.get('isLocked', defaultValue: false) ?? false;
+    await _loadSettings();
+    notifyListeners();
+  }
+
+  Future<void> _loadSettings() async {
+    try {
+      final biometricEnabled =
+          await _secureStorage.read(key: 'biometric_enabled');
+      _isBiometricEnabled = biometricEnabled == 'true';
+      notifyListeners();
+    } catch (e) {
+      debugPrint('설정 로드 중 오류 발생: $e');
+    }
+  }
+
+  Future<bool> authenticate() async {
+    if (kIsWeb) {
+      _isLocked = false;
+      notifyListeners();
+      return true;
+    }
+
+    try {
+      final canCheck = await _checkBiometrics();
+      if (!canCheck) {
+        _isLocked = false;
+        notifyListeners();
+        return true;
+      }
+
+      final authenticated = await _localAuth.authenticate(
+        localizedReason: '생체 인증을 사용하여 앱 잠금을 해제하세요.',
+        options: const AuthenticationOptions(
+          stickyAuth: true,
+          biometricOnly: true,
+        ),
+      );
+
+      if (authenticated) {
+        _isLocked = false;
+        await _appLockBox.put('isLocked', false);
+        notifyListeners();
+      }
+
+      return authenticated;
+    } catch (e) {
+      _isLocked = false;
+      notifyListeners();
+      return true;
+    }
+  }
+
+  Future<bool> _checkBiometrics() async {
+    if (kIsWeb) return false;
+    try {
+      return await _localAuth.canCheckBiometrics;
+    } catch (e) {
+      return false;
+    }
+  }
+
+  Future<void> toggleBiometricAuth() async {
+    if (kIsWeb) {
+      _isBiometricEnabled = false;
+      await _appLockBox.put('biometric_enabled', false);
+      notifyListeners();
+      return;
+    }
+
+    try {
+      final canCheck = await _checkBiometrics();
+      if (!canCheck) {
+        _isBiometricEnabled = false;
+        await _appLockBox.put('biometric_enabled', false);
+        notifyListeners();
+        return;
+      }
+
+      _isBiometricEnabled = !_isBiometricEnabled;
+      await _secureStorage.write(
+        key: 'biometric_enabled',
+        value: _isBiometricEnabled.toString(),
+      );
+      await _appLockBox.put('biometric_enabled', _isBiometricEnabled);
+      notifyListeners();
+    } catch (e) {
+      _isBiometricEnabled = false;
+      await _appLockBox.put('biometric_enabled', false);
+      notifyListeners();
+    }
+  }
+
+  void lock() {
+    if (_isBiometricEnabled) {
+      _isLocked = true;
+      notifyListeners();
+    }
+  }
+
+  Future<void> unlock() async {
+    _isLocked = false;
+    await _appLockBox.put('isLocked', false);
+    notifyListeners();
+  }
+
+  Future<void> enable() async {
+    _isEnabled = true;
+    await _secureStorage.write(key: _isEnabledKey, value: 'true');
+    notifyListeners();
+  }
+
+  Future<void> disable() async {
+    _isEnabled = false;
+    await _secureStorage.write(key: _isEnabledKey, value: 'false');
+    notifyListeners();
+  }
+
+  Future<void> refreshNotifications(BuildContext context) async {
+    final subscriptionProvider = Provider.of<SubscriptionProvider>(
+      context,
+      listen: false,
+    );
+    for (var subscription in subscriptionProvider.subscriptions) {
+      await NotificationService.scheduleSubscriptionNotification(subscription);
+    }
+  }
+}