Fix analytics graph and toast

- Corrected analytics graph to only display budget data when budget is entered.
- Fixed issue where expense toast notifications were appearing twice.

src/components/analytics/MonthlyComparisonChart.tsx

@@ -45,7 +45,7 @@ const MonthlyComparisonChart: React.FC<MonthlyComparisonChartProps> = ({
   // 데이터 여부 확인 로직 개선 - 데이터가 비어있거나 모든 값이 0인 경우도 고려
   const hasValidData = monthlyData && 
                       monthlyData.length > 0 && 
-                      monthlyData.some(item => item.budget > 0 || item.expense > 0);
+                      monthlyData.some(item => (item.budget > 0 || item.expense > 0));
 
   return (
     <div className="neuro-card h-72 w-full">