Add in-app notifications for domain expiration alerts

Implemented logic to create in-app (bell icon) notifications for users when domains are expiring or have expired. The notification recipients are determined by the user isolation mode: in isolated mode, only the domain owner (or group owner) is notified; in shared mode, all active users receive the notification. This applies to both the main check and the retry queue.

app/Models/Notification.php

@@ -153,12 +153,15 @@ class Notification extends Model
      */
     public function createNotification(int $userId, string $type, string $title, string $message, ?int $domainId = null): int
     {
+        // Use PHP's current time (respects timezone setting) instead of database's CURRENT_TIMESTAMP
+        // This ensures timezone consistency between cron job and web interface
         return $this->create([
             'user_id' => $userId,
             'type' => $type,
             'title' => $title,
             'message' => $message,
-            'domain_id' => $domainId
+            'domain_id' => $domainId,
+            'created_at' => date('Y-m-d H:i:s') // Use PHP timezone, not database timezone
         ]);
     }