Fix runtime default locale resolution

middleware.ts

@@ -2,7 +2,7 @@ import createMiddleware from "next-intl/middleware";
 import { NextResponse } from "next/server";
 import type { NextRequest } from "next/server";
 
-import { appLocales, createI18nRouting, routing } from "./i18n/routing";
+import { appLocales, createI18nRouting } from "./i18n/routing";
 import {
   fromDevelopmentAdminPath,
   getAdminBaseUrl,
@@ -14,7 +14,12 @@ import {
   isLegacyAdminPath,
   toInternalAdminPath,
 } from "./lib/admin-routing";
-import { getLocalizedPathWithDefault, stripLocalePrefix } from "./lib/locale";
+import {
+  FALLBACK_LOCALE,
+  getLocalizedPathWithDefault,
+  isSupportedLocale,
+  stripLocalePrefix,
+} from "./lib/locale";
 
 const ADMIN_SESSION_COOKIE = "moh_admin_session";
 
@@ -23,10 +28,6 @@ type SiteRuntimeState = {
   maintenanceEnabled: boolean;
 };
 
-function isSupportedLocale(locale: string | undefined): locale is (typeof appLocales)[number] {
-  return locale === "ar" || locale === "en" || locale === "de";
-}
-
 function getPathLocale(pathname: string, fallbackLocale: (typeof appLocales)[number]) {
   const locale = pathname.split("/")[1];
 
@@ -48,7 +49,7 @@ async function getSiteRuntimeState(request: NextRequest): Promise<SiteRuntimeSta
 
     if (!response.ok) {
       return {
-        defaultLocale: routing.defaultLocale,
+        defaultLocale: FALLBACK_LOCALE,
         maintenanceEnabled: false,
       };
     }
@@ -59,12 +60,12 @@ async function getSiteRuntimeState(request: NextRequest): Promise<SiteRuntimeSta
     };
 
     return {
-      defaultLocale: isSupportedLocale(data.defaultLocale) ? data.defaultLocale : routing.defaultLocale,
+      defaultLocale: isSupportedLocale(data.defaultLocale) ? data.defaultLocale : FALLBACK_LOCALE,
       maintenanceEnabled: data.maintenanceEnabled === true,
     };
   } catch {
     return {
-      defaultLocale: routing.defaultLocale,
+      defaultLocale: FALLBACK_LOCALE,
       maintenanceEnabled: false,
     };
   }