Major UI/UX and architecture improvements

- Implemented new navigation system with NavigationProvider and route management
- Added adaptive theme system with ThemeProvider for better theme handling
- Introduced glassmorphism design elements (app bars, scaffolds, cards)
- Added advanced animations (spring animations, page transitions, staggered lists)
- Implemented performance optimizations (memory manager, lazy loading)
- Refactored Analysis screen into modular components
- Added floating navigation bar with haptic feedback
- Improved subscription cards with swipe actions
- Enhanced skeleton loading with better animations
- Added cached network image support
- Improved overall app architecture and code organization

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

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

lib/providers/subscription_provider.dart

@@ -243,4 +243,83 @@ class SubscriptionProvider extends ChangeNotifier {
       await refreshSubscriptions();
     }
   }
+
+  /// 총 월간 지출을 계산합니다.
+  Future<double> calculateTotalExpense() async {
+    // 이미 존재하는 totalMonthlyExpense getter를 사용
+    return totalMonthlyExpense;
+  }
+
+  /// 최근 6개월의 월별 지출 데이터를 반환합니다.
+  Future<List<Map<String, dynamic>>> getMonthlyExpenseData() async {
+    final now = DateTime.now();
+    final List<Map<String, dynamic>> monthlyData = [];
+    
+    // 최근 6개월 데이터 생성
+    for (int i = 5; i >= 0; i--) {
+      final month = DateTime(now.year, now.month - i, 1);
+      double monthTotal = 0.0;
+      
+      // 해당 월에 활성화된 구독 계산
+      for (final subscription in _subscriptions) {
+        // 구독이 해당 월에 활성화되어 있었는지 확인
+        final subscriptionStartDate = subscription.nextBillingDate.subtract(
+          Duration(days: _getBillingCycleDays(subscription.billingCycle)),
+        );
+        
+        if (subscriptionStartDate.isBefore(DateTime(month.year, month.month + 1, 1)) &&
+            subscription.nextBillingDate.isAfter(month)) {
+          // 해당 월의 비용 계산 (이벤트 가격 고려)
+          if (subscription.isEventActive && 
+              subscription.eventStartDate != null &&
+              subscription.eventEndDate != null &&
+              month.isAfter(subscription.eventStartDate!) &&
+              month.isBefore(subscription.eventEndDate!)) {
+            monthTotal += subscription.eventPrice ?? subscription.monthlyCost;
+          } else {
+            monthTotal += subscription.monthlyCost;
+          }
+        }
+      }
+      
+      monthlyData.add({
+        'month': month,
+        'totalExpense': monthTotal,
+        'monthName': _getMonthLabel(month),
+      });
+    }
+    
+    return monthlyData;
+  }
+
+  /// 이벤트로 인한 총 절약액을 계산합니다.
+  double calculateTotalSavings() {
+    // 이미 존재하는 totalEventSavings getter를 사용
+    return totalEventSavings;
+  }
+
+  /// 결제 주기를 일 단위로 변환합니다.
+  int _getBillingCycleDays(String billingCycle) {
+    switch (billingCycle) {
+      case 'monthly':
+        return 30;
+      case 'yearly':
+        return 365;
+      case 'weekly':
+        return 7;
+      case 'quarterly':
+        return 90;
+      default:
+        return 30;
+    }
+  }
+
+  /// 월 라벨을 생성합니다.
+  String _getMonthLabel(DateTime month) {
+    final months = [
+      '1월', '2월', '3월', '4월', '5월', '6월',
+      '7월', '8월', '9월', '10월', '11월', '12월'
+    ];
+    return months[month.month - 1];
+  }
 }