refactor: handle null values in number formatting function to ensure consistent output

src/stores/utils/index.ts

@@ -124,7 +124,7 @@ export function deleteItem(items: unknown[], index: number) {
 }
 
 export function formatNumberDecimal(num: number, point: number = 2): string {
-  return num.toLocaleString('eng', {
+  return (num || 0).toLocaleString('eng', {
     minimumFractionDigits: point,
     maximumFractionDigits: point,
   });