Show app version on login

frontend/src/index.css

@@ -392,6 +392,7 @@ select {
 .auth-link { text-align: center; margin-top: 20px; font-size: 13px; color: var(--gray-500); }
 .auth-link a { color: var(--primary); font-weight: 600; text-decoration: none; }
 .auth-link a:hover { text-decoration: underline; }
+.auth-version { text-align: center; margin-top: 10px; font-size: 12px; color: var(--gray-400); }
 .auth-download-btn {
   justify-content: center;
 }

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 packageInfo from '../../../package.json';
 
 export default function LoginPage() {
   const { login } = useAuth();
@@ -83,6 +84,7 @@ export default function LoginPage() {
         <p className="auth-link">
           ¿No tienes cuenta? <Link to="/register">Registrarse</Link>
         </p>
+        <p className="auth-version">Versión {packageInfo.version}</p>
       </div>
     </div>
   );