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/detail/detail_event_section.dart

@@ -4,6 +4,7 @@ import '../../controllers/detail_screen_controller.dart';
 import '../../theme/app_colors.dart';
 import '../common/form_fields/currency_input_field.dart';
 import '../common/form_fields/date_picker_field.dart';
+import '../../l10n/app_localizations.dart';
 
 /// 이벤트 가격 섹션
 /// 할인 이벤트 정보를 관리하는 섹션입니다.
@@ -75,9 +76,9 @@ class DetailEventSection extends StatelessWidget {
                           ),
                         ),
                         const SizedBox(width: 12),
-                        const Text(
-                          '이벤트 가격',
-                          style: TextStyle(
+                        Text(
+                          AppLocalizations.of(context).eventPrice,
+                          style: const TextStyle(
                             fontSize: 18,
                             fontWeight: FontWeight.w700,
                             color: AppColors.darkNavy,
@@ -125,7 +126,7 @@ class DetailEventSection extends StatelessWidget {
                         const SizedBox(width: 8),
                         Expanded(
                           child: Text(
-                            '할인 또는 프로모션 가격을 설정하세요',
+                            AppLocalizations.of(context).eventPriceHint,
                             style: TextStyle(
                               fontSize: 14,
                               color: AppColors.darkNavy,
@@ -151,8 +152,8 @@ class DetailEventSection extends StatelessWidget {
                     onEndDateSelected: (date) {
                       controller.eventEndDate = date;
                     },
-                    startLabel: '시작일',
-                    endLabel: '종료일',
+                    startLabel: AppLocalizations.of(context).startDate,
+                    endLabel: AppLocalizations.of(context).endDate,
                     primaryColor: baseColor,
                   ),
                   const SizedBox(height: 20),
@@ -160,16 +161,16 @@ class DetailEventSection extends StatelessWidget {
                   CurrencyInputField(
                     controller: controller.eventPriceController,
                     currency: controller.currency,
-                    label: '이벤트 가격',
-                    hintText: '할인된 가격을 입력하세요',
+                    label: AppLocalizations.of(context).eventPrice,
+                    hintText: AppLocalizations.of(context).eventPriceHint,
                     validator: controller.isEventActive
                         ? (value) {
                             if (value == null || value.isEmpty) {
-                              return '이벤트 가격을 입력해주세요';
+                              return AppLocalizations.of(context).eventPriceRequired;
                             }
                             final price = double.tryParse(value.replaceAll(',', ''));
                             if (price == null || price <= 0) {
-                              return '올바른 가격을 입력해주세요';
+                              return AppLocalizations.of(context).invalidPrice;
                             }
                             return null;
                           }
@@ -233,7 +234,7 @@ class _DiscountBadge extends StatelessWidget {
               borderRadius: BorderRadius.circular(8),
             ),
             child: Text(
-              '$discountPercentage% 할인',
+              AppLocalizations.of(context).discountPercent.replaceAll('@', discountPercentage.toString()),
               style: const TextStyle(
                 color: Colors.white,
                 fontSize: 12,
@@ -243,9 +244,7 @@ class _DiscountBadge extends StatelessWidget {
           ),
           const SizedBox(width: 12),
           Text(
-            currency == 'KRW'
-                ? '₩${discountAmount.toInt().toString()}원 절약'
-                : '\$${discountAmount.toStringAsFixed(2)} 절약',
+            _getLocalizedDiscountAmount(context, currency, discountAmount),
             style: TextStyle(
               color: const Color(0xFF15803D),
               fontSize: 14,
@@ -256,4 +255,18 @@ class _DiscountBadge extends StatelessWidget {
       ),
     );
   }
+
+  String _getLocalizedDiscountAmount(BuildContext context, String currency, double amount) {
+    final loc = AppLocalizations.of(context);
+    switch (currency) {
+      case 'KRW':
+        return loc.discountAmountWon.replaceAll('@', amount.toInt().toString());
+      case 'JPY':
+        return loc.discountAmountYen.replaceAll('@', amount.toInt().toString());
+      case 'CNY':
+        return loc.discountAmountYuan.replaceAll('@', amount.toStringAsFixed(2));
+      default: // USD
+        return loc.discountAmountDollar.replaceAll('@', amount.toStringAsFixed(2));
+    }
+  }
 }