feat: migrate nextjs to rr7

apps/remix/app/routes/api+/locale.tsx

@@ -0,0 +1,19 @@
+import type { ActionFunctionArgs } from 'react-router';
+
+import { APP_I18N_OPTIONS } from '@documenso/lib/constants/i18n';
+
+import { langCookie } from '~/storage/lang-cookie.server';
+
+export const action = async ({ request }: ActionFunctionArgs) => {
+  const formData = await request.formData();
+  const lang = formData.get('lang') || '';
+
+  if (!APP_I18N_OPTIONS.supportedLangs.find((l) => l === lang)) {
+    throw new Response('Unsupported language', { status: 400 });
+  }
+
+  return new Response('OK', {
+    status: 200,
+    headers: { 'Set-Cookie': await langCookie.serialize(lang) },
+  });
+};