clean routes

apps/website/app/sponsor/settings/page.tsx

@@ -174,9 +174,10 @@ export default function SponsorSettingsPage() {
 
   const handleDeleteAccount = () => {
     if (confirm('Are you sure you want to delete your sponsor account? This action cannot be undone. All sponsorship data will be permanently removed.')) {
-      document.cookie = 'gridpilot_demo_mode=; path=/; expires=Thu, 01 Jan 1970 00:00:00 GMT';
-      document.cookie = 'gridpilot_sponsor_id=; path=/; expires=Thu, 01 Jan 1970 00:00:00 GMT';
-      router.push('/');
+      // Call logout API to clear session
+      fetch('/api/auth/logout', { method: 'POST' }).finally(() => {
+        router.push('/');
+      });
     }
   };