Fix data initialization issues

Addresses problems with budget display and data reset:
- Ensures budget data is correctly displayed after initialization.
- Fixes issue where daily and weekly budget data were missing.
- Corrects data reset to properly clear transaction data.

src/components/BudgetTabContent.tsx

@@ -33,8 +33,8 @@ const BudgetTabContent: React.FC<BudgetTabContentProps> = ({
   const actualPercentage = targetAmount > 0 ? Math.round(spentAmount / targetAmount * 100) : 0;
   const percentage = actualPercentage;
   
-  // 예산이 설정되었는지 여부 확인 (0이면 미설정으로 간주)
-  const isBudgetSet = targetAmount > 0;
+  // 예산이 설정되었는지 여부 확인 (정확히 0이면 미설정으로 간주)
+  const isBudgetSet = targetAmount !== 0;
 
   // 예산 초과 여부 계산
   const isOverBudget = spentAmount > targetAmount && targetAmount > 0;