Fix production web API routing

frontend/src/pages/auth/LoginPage.jsx

@@ -4,6 +4,7 @@ import { useAuth } from '../../contexts/AuthContext';
 import { Download, PenTool } from 'lucide-react';
 import toast from 'react-hot-toast';
 import { SESSION_EXPIRED_MESSAGE, translateApiError } from '../../utils/session';
+import { resolveAndroidApkUrl } from '../../config/api';
 import packageInfo from '../../../package.json';
 
 export default function LoginPage() {
@@ -12,8 +13,7 @@ export default function LoginPage() {
   const [searchParams, setSearchParams] = useSearchParams();
   const [form, setForm] = useState({ email: '', password: '' });
   const [loading, setLoading] = useState(false);
-  const apiBaseUrl = (import.meta.env.VITE_API_URL || 'http://localhost:4000').replace(/\/$/, '');
-  const androidApkUrl = `${apiBaseUrl}/downloads/android-apk`;
+  const androidApkUrl = resolveAndroidApkUrl();
   const showAndroidDownload = useMemo(() => {
     if (typeof navigator === 'undefined') return false;
     return /Android/i.test(navigator.userAgent || '');