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/floating_navigation_bar.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import '../theme/app_colors.dart';
 import 'glassmorphism_card.dart';
+import '../l10n/app_localizations.dart';
 
 class FloatingNavigationBar extends StatefulWidget {
   final int selectedIndex;
@@ -103,13 +104,13 @@ class _FloatingNavigationBarState extends State<FloatingNavigationBar>
                       children: [
                         _NavigationItem(
                           icon: Icons.home_rounded,
-                          label: '홈',
+                          label: AppLocalizations.of(context).home,
                           isSelected: widget.selectedIndex == 0,
                           onTap: () => _onItemTapped(0),
                         ),
                         _NavigationItem(
                           icon: Icons.analytics_rounded,
-                          label: '분석',
+                          label: AppLocalizations.of(context).analysis,
                           isSelected: widget.selectedIndex == 1,
                           onTap: () => _onItemTapped(1),
                         ),
@@ -118,13 +119,13 @@ class _FloatingNavigationBarState extends State<FloatingNavigationBar>
                         ),
                         _NavigationItem(
                           icon: Icons.qr_code_scanner_rounded,
-                          label: 'SMS',
+                          label: AppLocalizations.of(context).smsScanLabel,
                           isSelected: widget.selectedIndex == 3,
                           onTap: () => _onItemTapped(3),
                         ),
                         _NavigationItem(
                           icon: Icons.settings_rounded,
-                          label: '설정',
+                          label: AppLocalizations.of(context).settings,
                           isSelected: widget.selectedIndex == 4,
                           onTap: () => _onItemTapped(4),
                         ),