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/services/exchange_rate_service.dart

@@ -1,6 +1,5 @@
 import 'package:http/http.dart' as http;
 import 'dart:convert';
-import 'package:flutter/material.dart';
 import 'package:intl/intl.dart';
 
 /// 환율 정보 서비스 클래스

lib/services/notification_service.dart

@@ -152,13 +152,6 @@ class NotificationService {
     }
   }
 
-  // 알림 서비스가 초기화되었는지 확인하는 메서드
-  static bool _isInitialized() {
-    // 웹 플랫폼인 경우 항상 false 반환
-    if (_isWeb) return false;
-    // 초기화 플래그 확인
-    return _initialized;
-  }
 
   static Future<bool> requestPermission() async {
     final result = await _notifications
@@ -182,7 +175,7 @@ class NotificationService {
     }
     
     try {
-      final androidDetails = AndroidNotificationDetails(
+      const androidDetails = AndroidNotificationDetails(
         'subscription_channel',
         '구독 알림',
         channelDescription: '구독 관련 알림을 보여줍니다.',
@@ -257,7 +250,7 @@ class NotificationService {
     try {
       final notificationId = subscription.id.hashCode;
 
-      final androidDetails = AndroidNotificationDetails(
+      const androidDetails = AndroidNotificationDetails(
         'subscription_channel',
         '구독 알림',
         channelDescription: '구독 만료 알림을 보내는 채널입니다.',
@@ -265,13 +258,13 @@ class NotificationService {
         priority: Priority.high,
       );
 
-      final iosDetails = DarwinNotificationDetails(
+      const iosDetails = DarwinNotificationDetails(
         presentAlert: true,
         presentBadge: true,
         presentSound: true,
       );
 
-      final notificationDetails = NotificationDetails(
+      const notificationDetails = NotificationDetails(
         android: androidDetails,
         iOS: iosDetails,
       );

lib/services/sms_scanner.dart

@@ -80,7 +80,6 @@ class SmsScanner {
       final nextBillingDateStr = sms['nextBillingDate'] as String?;
       // 실제 반복 횟수 사용 (테스트 데이터에서는 이미 제공됨)
       final actualRepeatCount = repeatCount > 0 ? repeatCount : 1;
-      final isRecurring = (sms['isRecurring'] as bool?) ?? (repeatCount >= 2);
       final message = sms['message'] as String? ?? '';
 
       // 통화 단위 감지 - 메시지 내용과 서비스명 모두 검사
@@ -205,79 +204,7 @@ class SmsScanner {
     return serviceUrls[serviceName];
   }
 
-  bool _containsSubscriptionKeywords(String text) {
-    final keywords = [
-      '구독',
-      '결제',
-      '청구',
-      '정기',
-      '자동',
-      'subscription',
-      'payment',
-      'bill',
-      'invoice'
-    ];
-    return keywords
-        .any((keyword) => text.toLowerCase().contains(keyword.toLowerCase()));
-  }
 
-  double? _extractAmount(String text) {
-    final RegExp amountRegex = RegExp(r'(\d{1,3}(?:,\d{3})*(?:\.\d{2})?)');
-    final match = amountRegex.firstMatch(text);
-    if (match != null) {
-      final amountStr = match.group(1)?.replaceAll(',', '');
-      return double.tryParse(amountStr ?? '');
-    }
-    return null;
-  }
-
-  String? _extractServiceName(String text) {
-    final serviceNames = [
-      'Netflix',
-      'Spotify',
-      'Disney+',
-      'Apple Music',
-      'YouTube Premium',
-      'Amazon Prime',
-      'Microsoft 365',
-      'Google One',
-      'iCloud',
-      'Dropbox'
-    ];
-
-    for (final name in serviceNames) {
-      if (text.contains(name)) {
-        return name;
-      }
-    }
-    return null;
-  }
-
-  String _extractBillingCycle(String text) {
-    if (text.contains('월') || text.contains('month')) {
-      return 'monthly';
-    } else if (text.contains('년') || text.contains('year')) {
-      return 'yearly';
-    } else if (text.contains('주') || text.contains('week')) {
-      return 'weekly';
-    }
-    return 'monthly'; // 기본값
-  }
-
-  DateTime _extractNextBillingDate(String text) {
-    final RegExp dateRegex = RegExp(r'(\d{4}[-/]\d{2}[-/]\d{2})');
-    final match = dateRegex.firstMatch(text);
-    if (match != null) {
-      final dateStr = match.group(1);
-      if (dateStr != null) {
-        final date = DateTime.tryParse(dateStr);
-        if (date != null) {
-          return date;
-        }
-      }
-    }
-    return DateTime.now().add(const Duration(days: 30)); // 기본값: 30일 후
-  }
 
   // 메시지에서 통화 단위를 감지하는 함수
   String _detectCurrency(String message) {

lib/services/subscription_url_matcher.dart

@@ -1,4 +1,3 @@
-import 'package:flutter/material.dart';
 
 /// 구독 서비스와 웹사이트 URL 매칭을 처리하는 서비스 클래스
 class SubscriptionUrlMatcher {