Fix runtime default locale resolution

app/[locale]/(site)/about/page.tsx

@@ -4,7 +4,7 @@ import { getTranslations } from "next-intl/server";
 import { Container } from "@/components/layout/container";
 import { PageHero } from "@/components/layout/page-hero";
 import { AppCard } from "@/components/ui/app-card";
-import { resolveLocale } from "@/lib/locale";
+import { FALLBACK_LOCALE, resolveLocale } from "@/lib/locale";
 import { buildLocalizedMetadata } from "@/lib/metadata";
 
 type AboutPageProps = {
@@ -17,7 +17,7 @@ export const dynamic = "force-dynamic";
 
 export async function generateMetadata({ params }: AboutPageProps): Promise<Metadata> {
   const { locale } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const t = await getTranslations({ locale: localeKey, namespace: "aboutPage" });
 
   return await buildLocalizedMetadata({
@@ -30,7 +30,7 @@ export async function generateMetadata({ params }: AboutPageProps): Promise<Meta
 
 export default async function AboutPage({ params }: AboutPageProps) {
   const { locale } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const t = await getTranslations({ locale: localeKey, namespace: "aboutPage" });
 
   return (

app/[locale]/(site)/contact/actions.ts

@@ -59,8 +59,8 @@ function getStringValue(formData: FormData, key: string) {
 }
 
 export async function submitContactFormAction(formData: FormData) {
-  const locale = resolveLocale(String(formData.get("locale") ?? ""));
   const siteSettings = await getSiteSettings();
+  const locale = resolveLocale(String(formData.get("locale") ?? ""), siteSettings.defaultLocale);
   const contactPath = getLocalizedPath(locale, "/contact", siteSettings.defaultLocale);
 
   try {

app/[locale]/(site)/contact/page.tsx

@@ -8,7 +8,7 @@ import { MotionFade } from "@/components/motion-fade";
 import { ContactForm } from "@/components/site/contact-form";
 import { buildLocalizedMetadata } from "@/lib/metadata";
 import { getPublicContactProtectionSettings, getSiteSettings } from "@/lib/app-config";
-import { getLocalizedPath, resolveLocale } from "@/lib/locale";
+import { FALLBACK_LOCALE, getLocalizedPath, resolveLocale } from "@/lib/locale";
 import { AppCard } from "@/components/ui/app-card";
 import { CardContent, CardHeader, CardTitle } from "@/components/ui/card";
 
@@ -22,7 +22,7 @@ type ContactPageProps = {
 
 export async function generateMetadata({ params }: ContactPageProps): Promise<Metadata> {
   const { locale } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const t = await getTranslations({ locale: localeKey, namespace: "contactPage" });
 
   return await buildLocalizedMetadata({
@@ -35,7 +35,7 @@ export async function generateMetadata({ params }: ContactPageProps): Promise<Me
 
 export default async function ContactPage({ params }: ContactPageProps) {
   const { locale } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const [t, protection, siteSettings] = await Promise.all([
     getTranslations({ locale: localeKey, namespace: "contactPage" }),
     getPublicContactProtectionSettings(),

app/[locale]/(site)/layout.tsx

@@ -7,7 +7,7 @@ import { SiteFooter } from "@/components/layout/site-footer";
 import { SiteHeader } from "@/components/layout/site-header";
 import { isAdminAuthenticated } from "@/lib/admin-auth";
 import { getMaintenanceMode, getSiteSettings, getSiteSettingsMediaBindings } from "@/lib/app-config";
-import { getLocalizedPath, resolveLocale } from "@/lib/locale";
+import { FALLBACK_LOCALE, getLocalizedPath, resolveLocale } from "@/lib/locale";
 
 type SiteLayoutProps = {
   children: ReactNode;
@@ -23,7 +23,7 @@ export default async function SiteLayout({ children, params }: SiteLayoutProps)
   noStore();
   const { locale } = await params;
 
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const [maintenanceEnabled, mediaBindings, siteSettings] = await Promise.all([
     getMaintenanceMode(),
     getSiteSettingsMediaBindings(),

app/[locale]/(site)/page.tsx

@@ -21,7 +21,7 @@ import { buildLocalizedMetadata } from "@/lib/metadata";
 import { AppCard } from "@/components/ui/app-card";
 import { Button } from "@/components/ui/button";
 import { CardContent } from "@/components/ui/card";
-import { getLocalizedPath, resolveLocale } from "@/lib/locale";
+import { FALLBACK_LOCALE, getLocalizedPath, resolveLocale } from "@/lib/locale";
 
 type HomePageProps = {
   params: Promise<{
@@ -43,7 +43,7 @@ export const dynamic = "force-dynamic";
 
 export async function generateMetadata({ params }: HomePageProps): Promise<Metadata> {
   const { locale } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const [t, siteSettings] = await Promise.all([
     getTranslations({ locale: localeKey, namespace: "homepage" }),
     getSiteSettings(),
@@ -60,7 +60,7 @@ export async function generateMetadata({ params }: HomePageProps): Promise<Metad
 
 export default async function HomePage({ params }: HomePageProps) {
   const { locale } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const [t, marqueeSettings, siteSettings] = await Promise.all([
     getTranslations({ locale: localeKey, namespace: "homepage" }),
     getMarqueeSettings(),

app/[locale]/(site)/portfolio/[slug]/page.tsx

@@ -5,8 +5,9 @@ import { notFound } from "next/navigation";
 import { Container } from "@/components/layout/container";
 import { PageHero } from "@/components/layout/page-hero";
 import { PortfolioProjectDetail } from "@/components/site/portfolio-project-detail";
+import { getSiteSettings } from "@/lib/app-config";
 import { buildLocalizedMetadata } from "@/lib/metadata";
-import { resolveLocale } from "@/lib/locale";
+import { FALLBACK_LOCALE, resolveLocale } from "@/lib/locale";
 import {
   getLocalizedValue,
   getPublishedPortfolioProjectBySlug,
@@ -23,7 +24,7 @@ export const dynamic = "force-dynamic";
 
 export async function generateMetadata({ params }: PortfolioItemPageProps): Promise<Metadata> {
   const { locale, slug } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const item = await getPublishedPortfolioProjectBySlug(slug);
 
   if (!item) {
@@ -47,14 +48,17 @@ export default async function PortfolioItemPage({
   params,
 }: PortfolioItemPageProps) {
   const { locale, slug } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const item = await getPublishedPortfolioProjectBySlug(slug);
 
   if (!item) {
     notFound();
   }
 
-  const t = await getTranslations({ locale: localeKey, namespace: "portfolioDetail" });
+  const [t, siteSettings] = await Promise.all([
+    getTranslations({ locale: localeKey, namespace: "portfolioDetail" }),
+    getSiteSettings(),
+  ]);
 
   return (
     <>
@@ -64,7 +68,12 @@ export default async function PortfolioItemPage({
       />
 
       <Container size="wide" className="pb-12 lg:pb-16">
-        <PortfolioProjectDetail item={item} locale={localeKey} t={t} />
+        <PortfolioProjectDetail
+          item={item}
+          locale={localeKey}
+          defaultLocale={siteSettings.defaultLocale}
+          t={t}
+        />
       </Container>
     </>
   );

app/[locale]/(site)/portfolio/category/[slug]/page.tsx

@@ -6,8 +6,9 @@ import { Container } from "@/components/layout/container";
 import { PageHero } from "@/components/layout/page-hero";
 import { PortfolioCategoryFilter } from "@/components/site/portfolio-category-filter";
 import { PortfolioProjectGrid } from "@/components/site/portfolio-project-grid";
+import { getSiteSettings } from "@/lib/app-config";
 import { buildLocalizedMetadata } from "@/lib/metadata";
-import { resolveLocale } from "@/lib/locale";
+import { FALLBACK_LOCALE, resolveLocale } from "@/lib/locale";
 import {
   getActivePortfolioCategories,
   getActivePortfolioCategoryBySlug,
@@ -26,7 +27,7 @@ export const dynamic = "force-dynamic";
 
 export async function generateMetadata({ params }: PortfolioCategoryPageProps): Promise<Metadata> {
   const { locale, slug } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const t = await getTranslations({ locale: localeKey, namespace: "portfolioPage" });
   const category = await getActivePortfolioCategoryBySlug(slug);
 
@@ -51,9 +52,10 @@ export default async function PortfolioCategoryPage({
   params,
 }: PortfolioCategoryPageProps) {
   const { locale, slug } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
-  const t = await getTranslations({ locale: localeKey, namespace: "portfolioPage" });
+  const [t, siteSettings, categories, category, projects] = await Promise.all([
-  const [categories, category, projects] = await Promise.all([
+    getTranslations({ locale: localeKey, namespace: "portfolioPage" }),
+    getSiteSettings(),
     getActivePortfolioCategories(),
     getActivePortfolioCategoryBySlug(slug),
     getPublishedPortfolioProjects({ categorySlug: slug }),
@@ -75,12 +77,14 @@ export default async function PortfolioCategoryPage({
       <Container className="flex flex-col gap-section pb-12 lg:pb-16">
         <PortfolioCategoryFilter
           locale={localeKey}
+          defaultLocale={siteSettings.defaultLocale}
           categories={categories}
           allLabel={t("all")}
           activeCategorySlug={category.slug}
         />
         <PortfolioProjectGrid
           locale={localeKey}
+          defaultLocale={siteSettings.defaultLocale}
           projects={projects}
           emptyLabel={t("empty")}
           openLabel={t("open")}

app/[locale]/(site)/portfolio/category/page.tsx

@@ -1,6 +1,7 @@
 import { permanentRedirect } from "next/navigation";
 
-import { getLocalizedPath, resolveLocale } from "@/lib/locale";
+import { getSiteSettings } from "@/lib/app-config";
+import { FALLBACK_LOCALE, getLocalizedPath, resolveLocale } from "@/lib/locale";
 
 type PortfolioCategoryIndexPageProps = {
   params: Promise<{
@@ -12,7 +13,8 @@ export default async function PortfolioCategoryIndexPage({
   params,
 }: PortfolioCategoryIndexPageProps) {
   const { locale } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
+  const siteSettings = await getSiteSettings();
 
-  permanentRedirect(getLocalizedPath(localeKey, "/portfolio"));
+  permanentRedirect(getLocalizedPath(localeKey, "/portfolio", siteSettings.defaultLocale));
 }

app/[locale]/(site)/portfolio/page.tsx

@@ -6,8 +6,9 @@ import { Container } from "@/components/layout/container";
 import { PageHero } from "@/components/layout/page-hero";
 import { PortfolioCategoryFilter } from "@/components/site/portfolio-category-filter";
 import { PortfolioProjectGrid } from "@/components/site/portfolio-project-grid";
+import { getSiteSettings } from "@/lib/app-config";
 import { buildLocalizedMetadata } from "@/lib/metadata";
-import { getLocalizedPath, resolveLocale } from "@/lib/locale";
+import { FALLBACK_LOCALE, getLocalizedPath, resolveLocale } from "@/lib/locale";
 import { getActivePortfolioCategories, getPublishedPortfolioProjects } from "@/lib/portfolio";
 
 type PortfolioPageProps = {
@@ -23,7 +24,7 @@ export const dynamic = "force-dynamic";
 
 export async function generateMetadata({ params }: PortfolioPageProps): Promise<Metadata> {
   const { locale } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const t = await getTranslations({ locale: localeKey, namespace: "portfolioPage" });
 
   return await buildLocalizedMetadata({
@@ -42,12 +43,15 @@ export default async function PortfolioPage({
     params,
     searchParams,
   ]);
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
-  const t = await getTranslations({ locale: localeKey, namespace: "portfolioPage" });
+  const [t, siteSettings] = await Promise.all([
+    getTranslations({ locale: localeKey, namespace: "portfolioPage" }),
+    getSiteSettings(),
+  ]);
   const selectedCategory = resolvedSearchParams?.category ?? "";
 
   if (selectedCategory) {
-    redirect(getLocalizedPath(localeKey, `/portfolio/category/${selectedCategory}`));
+    redirect(getLocalizedPath(localeKey, `/portfolio/category/${selectedCategory}`, siteSettings.defaultLocale));
   }
 
   const [categories, projects] = await Promise.all([
@@ -65,9 +69,15 @@ export default async function PortfolioPage({
       />
 
       <Container className="flex flex-col gap-section pb-12 lg:pb-16">
-        <PortfolioCategoryFilter locale={localeKey} categories={categories} allLabel={t("all")} />
+        <PortfolioCategoryFilter
+          locale={localeKey}
+          defaultLocale={siteSettings.defaultLocale}
+          categories={categories}
+          allLabel={t("all")}
+        />
         <PortfolioProjectGrid
           locale={localeKey}
+          defaultLocale={siteSettings.defaultLocale}
           projects={projects}
           emptyLabel={t("empty")}
           openLabel={t("open")}

app/[locale]/(site)/success/page.tsx

@@ -8,7 +8,7 @@ import { MotionFade } from "@/components/motion-fade";
 import { HeroShell, HeroTitle } from "@/components/layout/site-hero";
 import { getSiteSettings } from "@/lib/app-config";
 import { buildLocalizedMetadata } from "@/lib/metadata";
-import { getLocalizedPath, resolveLocale } from "@/lib/locale";
+import { FALLBACK_LOCALE, getLocalizedPath, resolveLocale } from "@/lib/locale";
 import { AppCard } from "@/components/ui/app-card";
 import { Button } from "@/components/ui/button";
 import { CardContent } from "@/components/ui/card";
@@ -21,7 +21,7 @@ type SuccessPageProps = {
 
 export async function generateMetadata({ params }: SuccessPageProps): Promise<Metadata> {
   const { locale } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const t = await getTranslations({ locale: localeKey, namespace: "successPage" });
 
   return await buildLocalizedMetadata({
@@ -34,7 +34,7 @@ export async function generateMetadata({ params }: SuccessPageProps): Promise<Me
 
 export default async function SuccessPage({ params }: SuccessPageProps) {
   const { locale } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const [t, siteSettings] = await Promise.all([
     getTranslations({ locale: localeKey, namespace: "successPage" }),
     getSiteSettings(),

app/[locale]/coming-soon/page.tsx

@@ -8,7 +8,7 @@ import { MotionFade } from "@/components/motion-fade";
 import { HeroShell, HeroTitle } from "@/components/layout/site-hero";
 import { getSiteSettings } from "@/lib/app-config";
 import { buildLocalizedMetadata } from "@/lib/metadata";
-import { resolveLocale } from "@/lib/locale";
+import { FALLBACK_LOCALE, resolveLocale } from "@/lib/locale";
 
 type ComingSoonPageProps = {
   params: Promise<{
@@ -22,7 +22,7 @@ export const revalidate = 0;
 export async function generateMetadata({ params }: ComingSoonPageProps): Promise<Metadata> {
   noStore();
   const { locale } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const t = await getTranslations({ locale: localeKey, namespace: "comingSoon" });
   const siteSettings = await getSiteSettings();
 
@@ -40,7 +40,7 @@ export default async function ComingSoonPage({
 }: ComingSoonPageProps) {
   noStore();
   const { locale } = await params;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, FALLBACK_LOCALE);
   const [t, siteSettings] = await Promise.all([
     getTranslations({ locale: localeKey, namespace: "comingSoon" }),
     getSiteSettings(),

app/_admin/maintenance/actions.ts

@@ -7,7 +7,7 @@ import { routing } from "@/i18n/routing";
 import { getAdminAppPath, toInternalAdminPath } from "@/lib/admin-routing";
 import { clearAdminSessionCookie, isAdminAuthenticated } from "@/lib/admin-auth";
 import { getLocalizedPath } from "@/lib/locale";
-import { setMaintenanceMode } from "@/lib/app-config";
+import { getSiteSettings, setMaintenanceMode } from "@/lib/app-config";
 
 async function ensureAdmin() {
   if (!(await isAdminAuthenticated())) {
@@ -33,10 +33,11 @@ export async function updateMaintenanceModeAction(formData: FormData) {
   revalidatePath(toInternalAdminPath("/"));
   revalidatePath(toInternalAdminPath("/maintenance"));
   revalidatePath(toInternalAdminPath(redirectUrl.pathname));
+  const siteSettings = await getSiteSettings();
 
   for (const appLocale of routing.locales) {
-    revalidatePath(getLocalizedPath(appLocale), "layout");
+    revalidatePath(getLocalizedPath(appLocale, "/", siteSettings.defaultLocale), "layout");
-    revalidatePath(getLocalizedPath(appLocale, "/coming-soon"));
+    revalidatePath(getLocalizedPath(appLocale, "/coming-soon", siteSettings.defaultLocale));
   }
 
   redirect(`${redirectUrl.pathname}${redirectUrl.search}`);

app/_admin/marquee/actions.ts

@@ -6,7 +6,7 @@ import { isRedirectError } from "next/dist/client/components/redirect-error";
 
 import { getAdminAppPath, toInternalAdminPath } from "@/lib/admin-routing";
 import { clearAdminSessionCookie, isAdminAuthenticated } from "@/lib/admin-auth";
-import { updateMarqueeSettings } from "@/lib/app-config";
+import { getSiteSettings, updateMarqueeSettings } from "@/lib/app-config";
 import { routing } from "@/i18n/routing";
 import { getLocalizedPath } from "@/lib/locale";
 
@@ -27,10 +27,11 @@ function withMessage(pathname: string, type: "success" | "error", message: strin
 async function revalidateMarqueePages() {
   revalidatePath(toInternalAdminPath("/"));
   revalidatePath(toInternalAdminPath("/marquee"));
+  const siteSettings = await getSiteSettings();
 
   for (const locale of routing.locales) {
-    revalidatePath(getLocalizedPath(locale), "layout");
+    revalidatePath(getLocalizedPath(locale, "/", siteSettings.defaultLocale), "layout");
-    revalidatePath(getLocalizedPath(locale));
+    revalidatePath(getLocalizedPath(locale, "/", siteSettings.defaultLocale));
   }
 }
 

app/_admin/portfolio/actions.ts

@@ -16,6 +16,7 @@ import { removeManagedMediaFile } from "@/lib/media-storage";
 import { mediaFieldInputSchema } from "@/lib/media-validation";
 import { prisma } from "@/lib/prisma";
 import { isCheckedFormValue } from "@/lib/form-data";
+import { getSiteSettings } from "@/lib/app-config";
 import {
   assetInputSchema,
   categoryInputSchema,
@@ -92,9 +93,10 @@ async function revalidatePortfolioPages() {
   revalidatePath(toInternalAdminPath("/portfolio/categories"));
   revalidatePath(toInternalAdminPath("/portfolio/projects"));
   revalidatePath("/portfolio");
+  const siteSettings = await getSiteSettings();
 
   for (const locale of routing.locales) {
-    revalidatePath(getLocalizedPath(locale, "/portfolio"));
+    revalidatePath(getLocalizedPath(locale, "/portfolio", siteSettings.defaultLocale));
   }
 }
 
@@ -520,9 +522,10 @@ export async function saveProjectAction(formData: FormData) {
     await revalidatePortfolioPages();
     revalidatePath(toInternalAdminPath(`/portfolio/projects/${projectResult.project.id}`));
     revalidatePath(`/portfolio/${projectResult.project.slug}`);
+    const siteSettings = await getSiteSettings();
 
     for (const locale of routing.locales) {
-      revalidatePath(getLocalizedPath(locale, `/portfolio/${projectResult.project.slug}`));
+      revalidatePath(getLocalizedPath(locale, `/portfolio/${projectResult.project.slug}`, siteSettings.defaultLocale));
     }
 
     redirect(
@@ -591,9 +594,10 @@ export async function deleteProjectAction(formData: FormData) {
 
     await revalidatePortfolioPages();
     revalidatePath(`/portfolio/${project.slug}`);
+    const siteSettings = await getSiteSettings();
 
     for (const locale of routing.locales) {
-      revalidatePath(getLocalizedPath(locale, `/portfolio/${project.slug}`));
+      revalidatePath(getLocalizedPath(locale, `/portfolio/${project.slug}`, siteSettings.defaultLocale));
     }
 
     redirect(withMessage(getAdminAppPath("/portfolio"), "success", "Project deleted."));

app/_admin/site-settings/actions.ts

@@ -79,7 +79,7 @@ async function cleanupCreatedMedia(assetIds: string[], uploadedPaths: string[])
   }
 }
 
-async function revalidateSiteSettingsPages() {
+async function revalidateSiteSettingsPages(defaultLocale: SiteSettings["defaultLocale"]) {
   revalidatePath("/", "layout");
   revalidatePath(toInternalAdminPath("/"));
   revalidatePath(toInternalAdminPath("/site-settings"));
@@ -88,10 +88,10 @@ async function revalidateSiteSettingsPages() {
   const publicPaths = ["/", "/about", "/portfolio", "/contact", "/success", "/coming-soon"];
 
   for (const locale of routing.locales) {
-    revalidatePath(getLocalizedPath(locale), "layout");
+    revalidatePath(getLocalizedPath(locale, "/", defaultLocale), "layout");
 
     for (const path of publicPaths) {
-      revalidatePath(getLocalizedPath(locale, path));
+      revalidatePath(getLocalizedPath(locale, path, defaultLocale));
     }
   }
 }
@@ -259,7 +259,7 @@ export async function saveSiteBrandSettingsAction(formData: FormData) {
       ],
     });
 
-    await revalidateSiteSettingsPages();
+    await revalidateSiteSettingsPages(parsedSettings.defaultLocale);
     redirect(withMessage(getAdminAppPath("/site-settings/brand"), "success", "Einstellungen gespeichert."));
   } catch (error) {
     if (isRedirectError(error)) {
@@ -321,7 +321,7 @@ export async function saveSiteLocalizationSettingsAction(formData: FormData) {
     }
 
     await updateSiteSettings(parsedSettings);
-    await revalidateSiteSettingsPages();
+    await revalidateSiteSettingsPages(parsedSettings.defaultLocale);
     redirect(withMessage(getAdminAppPath("/site-settings/localization"), "success", "Einstellungen gespeichert."));
   } catch (error) {
     if (isRedirectError(error)) {

app/sitemap.ts

@@ -2,6 +2,7 @@ import type { MetadataRoute } from "next";
 import { unstable_noStore as noStore } from "next/cache";
 
 import { routing } from "@/i18n/routing";
+import { getSiteSettings } from "@/lib/app-config";
 import { getLocalizedPath } from "@/lib/locale";
 import { getPublishedPortfolioProjects } from "@/lib/portfolio";
 
@@ -15,10 +16,11 @@ function toAbsoluteUrl(pathname: string): string {
 
 function buildLocalizedEntries(
   pathname: string,
+  defaultLocale: "de" | "en" | "ar",
   options?: Pick<MetadataRoute.Sitemap[number], "changeFrequency" | "priority" | "lastModified">,
 ): MetadataRoute.Sitemap {
   return routing.locales.map((locale) => ({
-    url: toAbsoluteUrl(getLocalizedPath(locale, pathname)),
+    url: toAbsoluteUrl(getLocalizedPath(locale, pathname, defaultLocale)),
     lastModified: options?.lastModified,
     changeFrequency: options?.changeFrequency,
     priority: options?.priority,
@@ -27,6 +29,7 @@ function buildLocalizedEntries(
 
 export default async function sitemap(): Promise<MetadataRoute.Sitemap> {
   noStore();
+  const siteSettings = await getSiteSettings();
 
   let projects: Awaited<ReturnType<typeof getPublishedPortfolioProjects>> = [];
 
@@ -41,30 +44,30 @@ export default async function sitemap(): Promise<MetadataRoute.Sitemap> {
   );
 
   return [
-    ...buildLocalizedEntries("/", {
+    ...buildLocalizedEntries("/", siteSettings.defaultLocale, {
       changeFrequency: "weekly",
       priority: 1,
     }),
-    ...buildLocalizedEntries("/about", {
+    ...buildLocalizedEntries("/about", siteSettings.defaultLocale, {
       changeFrequency: "monthly",
       priority: 0.8,
     }),
-    ...buildLocalizedEntries("/portfolio", {
+    ...buildLocalizedEntries("/portfolio", siteSettings.defaultLocale, {
       changeFrequency: "weekly",
       priority: 0.9,
     }),
     ...categories.flatMap((category) =>
-      buildLocalizedEntries(`/portfolio/category/${category.slug}`, {
+      buildLocalizedEntries(`/portfolio/category/${category.slug}`, siteSettings.defaultLocale, {
         changeFrequency: "weekly",
         priority: 0.8,
       }),
     ),
-    ...buildLocalizedEntries("/contact", {
+    ...buildLocalizedEntries("/contact", siteSettings.defaultLocale, {
       changeFrequency: "monthly",
       priority: 0.7,
     }),
     ...projects.flatMap((project) =>
-      buildLocalizedEntries(`/portfolio/${project.slug}`, {
+      buildLocalizedEntries(`/portfolio/${project.slug}`, siteSettings.defaultLocale, {
         lastModified: project.publishedAt ?? undefined,
         changeFrequency: "monthly",
         priority: 0.8,

components/admin/portfolio-projects-overview.tsx

@@ -9,6 +9,7 @@ import { Badge } from "@/components/ui/badge";
 import { Button } from "@/components/ui/button";
 import { CardContent } from "@/components/ui/card";
 import { getAdminAppPath } from "@/lib/admin-routing";
+import { getSiteSettings } from "@/lib/app-config";
 import { getLocalizedPath } from "@/lib/locale";
 import { getLocalizedValue, type PortfolioCategoryView, type PortfolioProjectView } from "@/lib/portfolio";
 
@@ -28,11 +29,13 @@ const copy = {
   empty: "Noch keine Projekte vorhanden.",
 };
 
-export function PortfolioProjectsOverview({
+export async function PortfolioProjectsOverview({
   categories,
   projects,
   selectedCategory,
 }: PortfolioProjectsOverviewProps) {
+  const siteSettings = await getSiteSettings();
+
   return (
     <div className="space-y-6">
       <div className="flex flex-col gap-4 xl:flex-row xl:items-end xl:justify-between">
@@ -102,7 +105,7 @@ export function PortfolioProjectsOverview({
                 <div className="flex flex-wrap gap-3">
                   <Button asChild variant="outline">
                     <Link
-                      href={getLocalizedPath("de", `/portfolio/${project.slug}`)}
+                      href={getLocalizedPath("de", `/portfolio/${project.slug}`, siteSettings.defaultLocale)}
                       target="_blank"
                       rel="noreferrer"
                     >

components/layout/locale-toggle.tsx

@@ -17,7 +17,7 @@ const PENDING_TOAST_STORAGE_KEY = "mohfarawati-pending-toast";
 
 type LocaleToggleProps = {
   locale: string;
-  defaultLocale?: AppLocale;
+  defaultLocale: AppLocale;
   className?: string;
   showLabel?: boolean;
 };
@@ -30,7 +30,7 @@ const localeChangedMessages: Record<AppLocale, string> = {
 
 export function LocaleToggle({
   locale,
-  defaultLocale = "de",
+  defaultLocale,
   className,
   showLabel = false,
 }: LocaleToggleProps) {

components/site/portfolio-category-filter.tsx

@@ -7,6 +7,7 @@ import { cn } from "@/lib/utils";
 
 type PortfolioCategoryFilterProps = {
   locale: AppLocale;
+  defaultLocale: AppLocale;
   categories: PortfolioCategoryView[];
   allLabel: string;
   activeCategorySlug?: string;
@@ -14,6 +15,7 @@ type PortfolioCategoryFilterProps = {
 
 export function PortfolioCategoryFilter({
   locale,
+  defaultLocale,
   categories,
   allLabel,
   activeCategorySlug,
@@ -21,14 +23,14 @@ export function PortfolioCategoryFilter({
   return (
     <section className="flex flex-wrap gap-3">
       <CategoryLink
-        href={getLocalizedPath(locale, "/portfolio")}
+        href={getLocalizedPath(locale, "/portfolio", defaultLocale)}
         label={allLabel}
         active={!activeCategorySlug}
       />
       {categories.map((category) => (
         <CategoryLink
           key={category.id}
-          href={getLocalizedPath(locale, `/portfolio/category/${category.slug}`)}
+          href={getLocalizedPath(locale, `/portfolio/category/${category.slug}`, defaultLocale)}
           label={getLocalizedValue(category.name, locale)}
           active={activeCategorySlug === category.slug}
         />

components/site/portfolio-project-detail.tsx

@@ -24,6 +24,7 @@ import {
 type PortfolioProjectDetailProps = {
   item: PortfolioProjectView;
   locale: AppLocale;
+  defaultLocale: AppLocale;
   t: (key: "back" | "preview" | "openLink" | "gallery" | "download") => string;
 };
 
@@ -223,10 +224,12 @@ function BadgeCount({ count }: { count: number }) {
 function ProjectHeader({
   item,
   locale,
+  defaultLocale,
   t,
 }: {
   item: PortfolioProjectView;
   locale: AppLocale;
+  defaultLocale: AppLocale;
   t: PortfolioProjectDetailProps["t"];
 }) {
   return (
@@ -234,7 +237,7 @@ function ProjectHeader({
       <AppCard level={3}>
         <CardContent className="p-6 lg:p-10">
           <Button asChild variant="ghost" className="h-auto px-0 py-0 text-sm">
-            <Link href={getLocalizedPath(locale, "/portfolio")}>{t("back")}</Link>
+            <Link href={getLocalizedPath(locale, "/portfolio", defaultLocale)}>{t("back")}</Link>
           </Button>
 
           <h1 className="mt-5 text-3xl font-semibold text-foreground sm:text-4xl lg:text-5xl">
@@ -267,11 +270,12 @@ function ProjectHeader({
 function GridTemplate({
   item,
   locale,
+  defaultLocale,
   t,
 }: PortfolioProjectDetailProps) {
   return (
     <div className="space-y-6">
-      <ProjectHeader item={item} locale={locale} t={t} />
+      <ProjectHeader item={item} locale={locale} defaultLocale={defaultLocale} t={t} />
 
       {item.coverImagePath ? (
         <MotionFade delay={0.04}>
@@ -309,11 +313,12 @@ function GridTemplate({
 function StoryTemplate({
   item,
   locale,
+  defaultLocale,
   t,
 }: PortfolioProjectDetailProps) {
   return (
     <div className="space-y-8">
-      <ProjectHeader item={item} locale={locale} t={t} />
+      <ProjectHeader item={item} locale={locale} defaultLocale={defaultLocale} t={t} />
 
       {item.coverImagePath ? (
         <MotionFade delay={0.04}>
@@ -356,6 +361,7 @@ function StoryTemplate({
 function CaseStudyTemplate({
   item,
   locale,
+  defaultLocale,
   t,
 }: PortfolioProjectDetailProps) {
   const [challenge, solution, outcome, ...restSections] = item.sections;
@@ -365,7 +371,7 @@ function CaseStudyTemplate({
 
   return (
     <div className="space-y-8">
-      <ProjectHeader item={item} locale={locale} t={t} />
+      <ProjectHeader item={item} locale={locale} defaultLocale={defaultLocale} t={t} />
 
       <div className="grid gap-6 xl:grid-cols-[minmax(0,1.2fr)_420px]">
         <div className="space-y-6">
@@ -441,17 +447,18 @@ function CaseStudyTemplate({
 export function PortfolioProjectDetail({
   item,
   locale,
+  defaultLocale,
   t,
 }: PortfolioProjectDetailProps) {
   const viewMode = resolvePortfolioProjectViewMode(item.viewMode);
 
   if (viewMode === "STORY") {
-    return <StoryTemplate item={item} locale={locale} t={t} />;
+    return <StoryTemplate item={item} locale={locale} defaultLocale={defaultLocale} t={t} />;
   }
 
   if (viewMode === "CASE_STUDY") {
-    return <CaseStudyTemplate item={item} locale={locale} t={t} />;
+    return <CaseStudyTemplate item={item} locale={locale} defaultLocale={defaultLocale} t={t} />;
   }
 
-  return <GridTemplate item={item} locale={locale} t={t} />;
+  return <GridTemplate item={item} locale={locale} defaultLocale={defaultLocale} t={t} />;
 }

components/site/portfolio-project-grid.tsx

@@ -9,6 +9,7 @@ import { getLocalizedValue, type PortfolioProjectView } from "@/lib/portfolio";
 
 type PortfolioProjectGridProps = {
   locale: AppLocale;
+  defaultLocale: AppLocale;
   projects: PortfolioProjectView[];
   emptyLabel: string;
   openLabel: string;
@@ -16,6 +17,7 @@ type PortfolioProjectGridProps = {
 
 export function PortfolioProjectGrid({
   locale,
+  defaultLocale,
   projects,
   emptyLabel,
   openLabel,
@@ -27,7 +29,7 @@ export function PortfolioProjectGrid({
           <AppCard interactive>
             <CardContent className="p-5">
               <Link
-                href={getLocalizedPath(locale, `/portfolio/${item.slug}`)}
+                href={getLocalizedPath(locale, `/portfolio/${item.slug}`, defaultLocale)}
                 className="group block"
               >
                 <div className="flex items-center justify-between gap-3">

i18n/request.ts

@@ -1,15 +1,13 @@
 import { getRequestConfig } from "next-intl/server";
 
 import { getSiteSettings } from "@/lib/app-config";
-
+import { isSupportedLocale } from "@/lib/locale";
-import { routing } from "./routing";
 
 export default getRequestConfig(async ({ requestLocale }) => {
   const siteSettings = await getSiteSettings();
   const requestedLocale = await requestLocale;
   const locale =
-    requestedLocale &&
+    isSupportedLocale(requestedLocale)
-    routing.locales.includes(requestedLocale as (typeof routing.locales)[number])
       ? requestedLocale
       : siteSettings.defaultLocale;
 

lib/locale.ts

@@ -1,21 +1,23 @@
-import { routing } from "../i18n/routing";
+import { appLocales } from "../i18n/routing";
 
-export type AppLocale = (typeof routing.locales)[number];
+export type AppLocale = (typeof appLocales)[number];
 
-export function resolveLocale(locale: string): AppLocale {
+export const FALLBACK_LOCALE: AppLocale = "de";
-  if (locale === "en" || locale === "ar") {
+
-    return locale;
+export function isSupportedLocale(locale: string | undefined | null): locale is AppLocale {
+  return locale === "de" || locale === "en" || locale === "ar";
 }
 
-  return routing.defaultLocale;
+export function resolveLocale(locale: string | undefined | null, fallbackLocale: AppLocale): AppLocale {
+  return isSupportedLocale(locale) ? locale : fallbackLocale;
 }
 
 export function getDirection(locale: string): "ltr" | "rtl" {
-  return resolveLocale(locale) === "ar" ? "rtl" : "ltr";
+  return locale === "ar" ? "rtl" : "ltr";
 }
 
 export function stripLocalePrefix(pathname: string): string {
-  for (const locale of routing.locales) {
+  for (const locale of appLocales) {
     if (pathname === `/${locale}`) {
       return "/";
     }
@@ -31,7 +33,7 @@ export function stripLocalePrefix(pathname: string): string {
 export function getLocalizedPath(
   locale: string,
   pathname = "/",
-  defaultLocale: AppLocale = routing.defaultLocale,
+  defaultLocale: AppLocale,
 ): string {
   return getLocalizedPathWithDefault(locale, pathname, defaultLocale);
 }
@@ -39,9 +41,9 @@ export function getLocalizedPath(
 export function getLocalizedPathWithDefault(
   locale: string,
   pathname = "/",
-  defaultLocale: AppLocale = routing.defaultLocale,
+  defaultLocale: AppLocale,
 ): string {
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, defaultLocale);
   const normalizedPath = pathname === "" ? "/" : pathname;
   const strippedPath = stripLocalePrefix(normalizedPath);
 

lib/metadata.ts

@@ -1,6 +1,6 @@
 import type { Metadata } from "next";
 
-import { routing } from "../i18n/routing";
+import { appLocales } from "../i18n/routing";
 import {
   PAGE_TITLE_TOKEN,
   SITE_NAME_TOKEN,
@@ -22,9 +22,9 @@ function toAbsoluteUrl(pathname: string): string {
   return new URL(pathname, getSiteUrl()).toString();
 }
 
-export function buildLocaleAlternates(pathname: string, defaultLocale = routing.defaultLocale) {
+export function buildLocaleAlternates(pathname: string, defaultLocale: AppLocale) {
   const languages = Object.fromEntries(
-    routing.locales.map((locale) => [locale, toAbsoluteUrl(getLocalizedPathWithDefault(locale, pathname, defaultLocale))]),
+    appLocales.map((locale) => [locale, toAbsoluteUrl(getLocalizedPathWithDefault(locale, pathname, defaultLocale))]),
   ) as Record<AppLocale, string>;
 
   return {
@@ -120,8 +120,8 @@ export async function buildLocalizedMetadata({
   description,
   applyTitleTemplate,
 }: LocalizedMetadataInput): Promise<Metadata> {
-  const localeKey = resolveLocale(locale);
   const [settings, bindings] = await Promise.all([getSiteSettings(), getSiteSettingsMediaBindings()]);
+  const localeKey = resolveLocale(locale, settings.defaultLocale);
 
   return buildLocalizedMetadataFromConfig({
     settings,
@@ -152,7 +152,7 @@ export function buildLocalizedMetadataFromConfig(input: {
     description,
     applyTitleTemplate = true,
   } = input;
-  const localeKey = resolveLocale(locale);
+  const localeKey = resolveLocale(locale, settings.defaultLocale);
   const localeSettings = settings.locales[localeKey];
   const resolvedDescription = description?.trim() || localeSettings.siteDescription;
   const resolvedTitle = applyTitleTemplate
@@ -167,7 +167,7 @@ export function buildLocalizedMetadataFromConfig(input: {
     openGraph: {
       title: resolvedTitle,
       description: resolvedDescription,
-      url: toAbsoluteUrl(getLocalizedPath(localeKey, pathname)),
+      url: toAbsoluteUrl(getLocalizedPath(localeKey, pathname, settings.defaultLocale)),
       siteName: localeSettings.siteName,
       locale: localeKey,
       type: "website",

lib/toast.tsx

@@ -6,7 +6,7 @@ import {
   type ToastPosition,
 } from "react-hot-toast";
 
-import { resolveLocale } from "@/lib/locale";
+import { FALLBACK_LOCALE, resolveLocale } from "@/lib/locale";
 
 type ToastVariant = "default" | "success" | "error" | "loading";
 
@@ -14,13 +14,13 @@ type ToastMessage = string;
 
 function getCurrentLocale() {
   if (typeof window === "undefined") {
-    return "de" as const;
+    return FALLBACK_LOCALE;
   }
 
   const pathname = window.location.pathname;
-  const maybeLocale = pathname.split("/")[1] || "de";
+  const maybeLocale = pathname.split("/")[1] || FALLBACK_LOCALE;
 
-  return resolveLocale(maybeLocale);
+  return resolveLocale(maybeLocale, FALLBACK_LOCALE);
 }
 
 function getToastPosition(isArabic: boolean): ToastPosition {

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,
     };
   }

tests/locale.test.ts

@@ -1,8 +1,22 @@
 import { describe, expect, it } from "vitest";
 
-import { getLocalizedPathWithDefault } from "../lib/locale";
+import { FALLBACK_LOCALE, getLocalizedPathWithDefault, isSupportedLocale, resolveLocale } from "../lib/locale";
 
 describe("locale path helpers", () => {
+  it("recognizes supported locales explicitly", () => {
+    expect(isSupportedLocale("ar")).toBe(true);
+    expect(isSupportedLocale("en")).toBe(true);
+    expect(isSupportedLocale("de")).toBe(true);
+    expect(isSupportedLocale("fr")).toBe(false);
+    expect(isSupportedLocale(undefined)).toBe(false);
+  });
+
+  it("resolves invalid locales with an explicit fallback", () => {
+    expect(resolveLocale("ar", "de")).toBe("ar");
+    expect(resolveLocale("fr", "en")).toBe("en");
+    expect(resolveLocale("", FALLBACK_LOCALE)).toBe("de");
+  });
+
   it("keeps the configured default locale on the bare domain", () => {
     expect(getLocalizedPathWithDefault("ar", "/", "ar")).toBe("/");
     expect(getLocalizedPathWithDefault("de", "/", "ar")).toBe("/de");

tests/metadata.test.ts

@@ -4,6 +4,7 @@ import { buildDefaultSiteSettings } from "../lib/site-settings";
 import {
   applyTitleTemplateFn,
   buildAppMetadataFromConfig,
+  buildLocaleAlternates,
   buildLocalizedMetadataFromConfig,
 } from "../lib/metadata";
 
@@ -96,4 +97,44 @@ describe("metadata helpers", () => {
 
     expect(metadata.title).toBe("اسم الموقع");
   });
+
+  it("builds alternates and canonical from the runtime default locale", () => {
+    const alternates = buildLocaleAlternates("/about", "ar");
+
+    expect(alternates.canonical).toBe("https://mohfarawati.de/about");
+    expect(alternates.languages.ar).toBe("https://mohfarawati.de/about");
+    expect(alternates.languages.de).toBe("https://mohfarawati.de/de/about");
+    expect(alternates.languages["x-default"]).toBe("https://mohfarawati.de/about");
+  });
+
+  it("builds localized metadata urls against the configured default locale", () => {
+    const settings = buildDefaultSiteSettings("Studio Moh");
+    settings.defaultLocale = "ar";
+
+    const metadata = buildLocalizedMetadataFromConfig({
+      settings,
+      bindings: {
+        siteLogoLight: null,
+        siteLogoDark: null,
+        favicon: null,
+        defaultOgImage: null,
+      },
+      locale: "de",
+      pathname: "/about",
+      title: "About",
+    });
+
+    expect(metadata.alternates).toMatchObject({
+      canonical: "https://mohfarawati.de/about",
+      languages: {
+        ar: "https://mohfarawati.de/about",
+        de: "https://mohfarawati.de/de/about",
+        en: "https://mohfarawati.de/en/about",
+        "x-default": "https://mohfarawati.de/about",
+      },
+    });
+    expect(metadata.openGraph).toMatchObject({
+      url: "https://mohfarawati.de/de/about",
+    });
+  });
 });

tests/middleware.test.ts

@@ -0,0 +1,118 @@
+import { NextResponse } from "next/server";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+const createMiddlewareMock = vi.fn();
+const intlHandlerMock = vi.fn(() => NextResponse.next());
+
+vi.mock("next-intl/middleware", () => ({
+  default: createMiddlewareMock,
+}));
+
+vi.mock("../lib/admin-routing", () => ({
+  fromDevelopmentAdminPath: (pathname: string) => pathname,
+  getAdminBaseUrl: () => "https://admin.example.com",
+  getRequestHostname: (_forwardedHost: string | null, host: string | null, hostname: string) => host ?? hostname,
+  isDevelopmentAdminPath: () => false,
+  isAdminHost: () => false,
+  hasDedicatedAdminHost: () => false,
+  isInternalAdminPath: () => false,
+  isLegacyAdminPath: () => false,
+  toInternalAdminPath: (pathname: string) => pathname,
+}));
+
+function createMockRequest(url: string) {
+  const nextUrl = new URL(url) as URL & { clone: () => URL };
+  nextUrl.clone = () => new URL(nextUrl.toString());
+
+  return {
+    url,
+    nextUrl,
+    headers: new Headers({
+      host: nextUrl.host,
+    }),
+    cookies: {
+      has: vi.fn(() => false),
+    },
+  };
+}
+
+describe("middleware locale runtime config", () => {
+  beforeEach(() => {
+    vi.resetModules();
+    createMiddlewareMock.mockReset();
+    intlHandlerMock.mockReset();
+    intlHandlerMock.mockReturnValue(NextResponse.next());
+    createMiddlewareMock.mockReturnValue(intlHandlerMock);
+  });
+
+  afterEach(() => {
+    vi.unstubAllGlobals();
+  });
+
+  it("passes the runtime default locale into next-intl middleware", async () => {
+    vi.stubGlobal(
+      "fetch",
+      vi.fn(async () => ({
+        ok: true,
+        json: async () => ({
+          defaultLocale: "ar",
+          maintenanceEnabled: false,
+        }),
+      })),
+    );
+
+    const { default: middleware } = await import("../middleware");
+    const request = createMockRequest("https://example.com/");
+
+    await middleware(request as never);
+
+    expect(createMiddlewareMock).toHaveBeenCalledTimes(1);
+    expect(createMiddlewareMock).toHaveBeenCalledWith(
+      expect.objectContaining({
+        defaultLocale: "ar",
+      }),
+    );
+    expect(intlHandlerMock).toHaveBeenCalledTimes(1);
+  });
+
+  it("falls back safely when the runtime locale lookup fails", async () => {
+    vi.stubGlobal(
+      "fetch",
+      vi.fn(async () => {
+        throw new Error("network failed");
+      }),
+    );
+
+    const { default: middleware } = await import("../middleware");
+    const request = createMockRequest("https://example.com/");
+
+    await middleware(request as never);
+
+    expect(createMiddlewareMock).toHaveBeenCalledWith(
+      expect.objectContaining({
+        defaultLocale: "de",
+      }),
+    );
+  });
+
+  it("redirects maintenance traffic using the runtime default locale", async () => {
+    vi.stubGlobal(
+      "fetch",
+      vi.fn(async () => ({
+        ok: true,
+        json: async () => ({
+          defaultLocale: "ar",
+          maintenanceEnabled: true,
+        }),
+      })),
+    );
+
+    const { default: middleware } = await import("../middleware");
+    const request = createMockRequest("https://example.com/");
+
+    const response = await middleware(request as never);
+
+    expect(response.headers.get("location")).toBe("https://example.com/coming-soon");
+    expect(intlHandlerMock).not.toHaveBeenCalled();
+  });
+});