fix: robust logout session clearing with cookie cleanup and isLoggingOut guard

- Clear next-auth session cookies directly as backup in logout page
- Add isLoggingOut localStorage flag to prevent TokenSync/PresenceProvider from restoring tokens
- Clear isLoggingOut flag on login page load as safety net
- Add createdAt to AgentSubscription interface (fixes build error)
- Add /education to public routes in middleware

src/app/(auth)/login/page.tsx

@@ -13,6 +13,11 @@ export default function LoginPage() {
   const [error, setError] = useState('');
   const [loading, setLoading] = useState(false);
 
+  // Safety net: clear logout flag when login page loads
+  if (typeof window !== 'undefined') {
+    localStorage.removeItem('isLoggingOut');
+  }
+
   const handleSubmit = async (e: React.FormEvent) => {
     e.preventDefault();
     setLoading(true);