another step

client/src/lib/api/server.ts

@@ -9,6 +9,7 @@ import { headers } from 'next/headers';
 
 import { API_URL } from '@/config';
 import { COOKIE_NAMES } from '@/lib/cookies';
+import { HEADER_NAMES } from '@/constants';
 import { getServerCookie } from '@/lib/cookies/server';
 import { ApiError } from './errors';
 
@@ -26,7 +27,7 @@ export async function serverFetch<T>(path: string, options?: RequestInit): Promi
   let locale = 'fa';
   try {
     const reqHeaders = await headers();
-    locale = reqHeaders.get('x-next-intl-locale') ?? 'fa';
+    locale = reqHeaders.get(HEADER_NAMES.LOCALE) ?? 'fa';
   } catch {
     // Outside request context (build-time prerendering) — use default locale
   }