feat: 다국어 지원 및 다중 통화 환율 변환 기능 확대

- ExchangeRateService에 JPY, CNY 환율 지원 추가
- 구독 서비스별 다국어 표시 이름 지원
- 분석 화면 차트 및 UI/UX 개선
- 설정 화면 전면 리팩토링
- SMS 스캔 기능 사용성 개선
- 전체 앱 다국어 번역 확대

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

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

lib/widgets/common/form_fields/currency_selector.dart

@@ -2,7 +2,7 @@ import 'package:flutter/material.dart';
 import '../../../theme/app_colors.dart';
 
 /// 통화 선택 위젯
-/// KRW(원화)와 USD(달러) 중 선택할 수 있습니다.
+/// KRW(원화), USD(달러), JPY(엔화), CNY(위안화) 중 선택할 수 있습니다.
 class CurrencySelector extends StatelessWidget {
   final String currency;
   final ValueChanged<String> onChanged;
@@ -17,22 +17,48 @@ class CurrencySelector extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return Row(
+    return Column(
       children: [
-        _CurrencyOption(
-          label: '₩',
-          value: 'KRW',
-          isSelected: currency == 'KRW',
-          onTap: () => onChanged('KRW'),
-          isGlassmorphism: isGlassmorphism,
+        Row(
+          children: [
+            _CurrencyOption(
+              label: '₩',
+              value: 'KRW',
+              isSelected: currency == 'KRW',
+              onTap: () => onChanged('KRW'),
+              isGlassmorphism: isGlassmorphism,
+            ),
+            const SizedBox(width: 8),
+            _CurrencyOption(
+              label: '\$',
+              value: 'USD',
+              isSelected: currency == 'USD',
+              onTap: () => onChanged('USD'),
+              isGlassmorphism: isGlassmorphism,
+            ),
+          ],
         ),
-        const SizedBox(width: 8),
-        _CurrencyOption(
-          label: '\$',
-          value: 'USD',
-          isSelected: currency == 'USD',
-          onTap: () => onChanged('USD'),
-          isGlassmorphism: isGlassmorphism,
+        const SizedBox(height: 8),
+        Row(
+          children: [
+            _CurrencyOption(
+              label: '¥',
+              value: 'JPY',
+              subtitle: 'JPY',
+              isSelected: currency == 'JPY',
+              onTap: () => onChanged('JPY'),
+              isGlassmorphism: isGlassmorphism,
+            ),
+            const SizedBox(width: 8),
+            _CurrencyOption(
+              label: '¥',
+              value: 'CNY',
+              subtitle: 'CNY',
+              isSelected: currency == 'CNY',
+              onTap: () => onChanged('CNY'),
+              isGlassmorphism: isGlassmorphism,
+            ),
+          ],
         ),
       ],
     );
@@ -43,6 +69,7 @@ class CurrencySelector extends StatelessWidget {
 class _CurrencyOption extends StatelessWidget {
   final String label;
   final String value;
+  final String? subtitle;
   final bool isSelected;
   final VoidCallback onTap;
   final bool isGlassmorphism;
@@ -50,6 +77,7 @@ class _CurrencyOption extends StatelessWidget {
   const _CurrencyOption({
     required this.label,
     required this.value,
+    this.subtitle,
     required this.isSelected,
     required this.onTap,
     required this.isGlassmorphism,
@@ -71,13 +99,29 @@ class _CurrencyOption extends StatelessWidget {
             border: _getBorder(),
           ),
           child: Center(
-            child: Text(
-              label,
-              style: TextStyle(
-                fontSize: 18,
-                fontWeight: FontWeight.w600,
-                color: _getTextColor(),
-              ),
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                Text(
+                  label,
+                  style: TextStyle(
+                    fontSize: 18,
+                    fontWeight: FontWeight.w600,
+                    color: _getTextColor(),
+                  ),
+                ),
+                if (subtitle != null) ...[
+                  const SizedBox(height: 2),
+                  Text(
+                    subtitle!,
+                    style: TextStyle(
+                      fontSize: 10,
+                      fontWeight: FontWeight.w500,
+                      color: _getTextColor().withValues(alpha: 0.8),
+                    ),
+                  ),
+                ],
+              ],
             ),
           ),
         ),