Upgrade app to Next.js 16

app/root/marquee/actions.ts

@@ -2,7 +2,7 @@
 
 import { revalidatePath } from "next/cache";
 import { redirect } from "next/navigation";
-import { isRedirectError } from "next/dist/client/components/redirect";
+import { isRedirectError } from "next/dist/client/components/redirect-error";
 
 import { toInternalAdminPath } from "@/lib/admin-routing";
 import { clearAdminSessionCookie, isAdminAuthenticated } from "@/lib/admin-auth";
@@ -10,9 +10,9 @@ import { updateMarqueeSettings } from "@/lib/app-config";
 import { routing } from "@/i18n/routing";
 import { getLocalizedPath } from "@/lib/locale";
 
-function ensureAdmin() {
-  if (!isAdminAuthenticated()) {
-    clearAdminSessionCookie();
+async function ensureAdmin() {
+  if (!(await isAdminAuthenticated())) {
+    await clearAdminSessionCookie();
     redirect("/");
   }
 }
@@ -35,7 +35,7 @@ async function revalidateMarqueePages() {
 }
 
 export async function saveMarqueeSettingsAction(formData: FormData) {
-  ensureAdmin();
+  await ensureAdmin();
 
   try {
     const germanSettings = {