Update WalletService and WalletPage to handle timestamps more robustly

- Modified WalletService to set a default timestamp when payment time is not provided, ensuring consistent date handling.
- Enhanced WalletPage to validate timestamps before formatting, preventing potential errors and improving user experience by displaying a placeholder for invalid timestamps.

These changes improve the reliability of transaction data presentation in the wallet module.

src/modules/wallet/views/WalletPage.vue

@@ -38,15 +38,20 @@ const totalBalance = computed(() => {
 // Get transactions grouped by date
 const groupedTransactions = computed(() => {
   const groups: Record<string, typeof transactions.value> = {}
-  
+
   transactions.value.forEach((tx: any) => {
-    const dateKey = format(tx.timestamp, 'MMMM d, yyyy')
+    // Ensure timestamp is valid before formatting
+    const timestamp = tx.timestamp instanceof Date && !isNaN(tx.timestamp.getTime())
+      ? tx.timestamp
+      : new Date()
+
+    const dateKey = format(timestamp, 'MMMM d, yyyy')
     if (!groups[dateKey]) {
       groups[dateKey] = []
     }
     groups[dateKey].push(tx)
   })
-  
+
   return groups
 })
 
@@ -189,7 +194,11 @@ onMounted(() => {
                       <div>
                         <p class="font-medium">{{ tx.description }}</p>
                         <div class="flex items-center gap-2 text-sm text-muted-foreground">
-                          <span>{{ format(tx.timestamp, 'HH:mm') }}</span>
+                          <span>{{
+                            tx.timestamp instanceof Date && !isNaN(tx.timestamp.getTime())
+                              ? format(tx.timestamp, 'HH:mm')
+                              : '--:--'
+                          }}</span>
                           <Badge :variant="getStatusColor(tx.status)" class="text-xs">
                             {{ tx.status }}
                           </Badge>