fix(checkout-returnto): checkout login: return user to checkout after sign in

project/frontend/src/app/auth/login/page.tsx

@@ -1,12 +1,14 @@
 'use client';
-import { useState } from 'react';
-import { useRouter } from 'next/navigation';
+import { Suspense, useState } from 'react';
+import { useRouter, useSearchParams } from 'next/navigation';
 import Link from 'next/link';
 import { useAuth } from '@/contexts/AuthContext';
 
-export default function LoginPage() {
+function LoginForm() {
   const { login } = useAuth();
   const router = useRouter();
+  const searchParams = useSearchParams();
+  const returnTo = searchParams.get('returnTo') ?? '/';
   const [email, setEmail] = useState('');
   const [password, setPassword] = useState('');
   const [error, setError] = useState('');
@@ -19,7 +21,7 @@ export default function LoginPage() {
     const result = await login(email, password);
     setLoading(false);
     if (result.ok) {
-      router.push('/');
+      router.push(returnTo);
     } else {
       setError(result.error || 'Credenciales inválidas');
     }
@@ -82,3 +84,11 @@ export default function LoginPage() {
     </div>
   );
 }
+
+export default function LoginPage() {
+  return (
+    <Suspense>
+      <LoginForm />
+    </Suspense>
+  );
+}