feat: complete MDX migration, stabilize environment & verify via E2E tests

Former-commit-id: ec3e64156a2e182535cbdcf0d975cd54603a517d

app/[locale]/not-found.tsx

@@ -1,87 +1,19 @@
 import { getTranslations } from 'next-intl/server';
 import { Container, Button, Heading } from '@/components/ui';
 import Scribble from '@/components/Scribble';
-import { getPayload } from 'payload';
-import configPromise from '@payload-config';
-import { headers } from 'next/headers';
 import ClientNotFoundTracker from '@/components/analytics/ClientNotFoundTracker';
 
 export default async function NotFound() {
   console.log('--- NOT FOUND RENDERED ---');
   const t = await getTranslations('Error.notFound');
 
-  // Try to determine the requested path
-  const headersList = await headers();
-  const urlPath = headersList.get('x-invoke-path') || '';
-
+  // Suggested URL logic removed along with Payload CMS
   let suggestedUrl = null;
   let suggestedLang = null;
 
-  // If we have a path, try to see if the last segment (slug) exists in ANY locale
-  if (urlPath) {
-    const slug = urlPath.split('/').filter(Boolean).pop();
-    if (slug) {
-      try {
-        const payload = await getPayload({ config: configPromise });
-
-        // Check posts
-        const postRes = await payload.find({
-          collection: 'posts',
-          where: { slug: { equals: slug } },
-          locale: 'all',
-          limit: 1,
-        });
-
-        // Check competences
-        const competenceRes =
-          postRes.docs.length === 0
-            ? await payload.find({
-                collection: 'competences',
-                where: { slug: { equals: slug } },
-                locale: 'all',
-                limit: 1,
-              })
-            : { docs: [] };
-
-        // Check pages
-        const pageRes =
-          postRes.docs.length === 0 && competenceRes.docs.length === 0
-            ? await payload.find({
-                collection: 'pages',
-                where: { slug: { equals: slug } },
-                locale: 'all',
-                limit: 1,
-              })
-            : { docs: [] };
-
-        const anyDoc = postRes.docs[0] || competenceRes.docs[0] || pageRes.docs[0];
-
-        if (anyDoc) {
-          // If the doc exists, we can figure out its native locale or
-          // offer the alternative locale (if we are in 'de', offer 'en')
-          const currentLocale = urlPath.startsWith('/en') ? 'en' : 'de';
-          const alternativeLocale = currentLocale === 'de' ? 'en' : 'de';
-
-          suggestedLang = alternativeLocale === 'de' ? 'Deutsch' : 'English';
-
-          // Reconstruct the URL for the alternative locale
-          const pathParts = urlPath.split('/').filter(Boolean);
-          if (pathParts.length > 0 && (pathParts[0] === 'en' || pathParts[0] === 'de')) {
-            pathParts[0] = alternativeLocale;
-          } else {
-            pathParts.unshift(alternativeLocale);
-          }
-          suggestedUrl = '/' + pathParts.join('/');
-        }
-      } catch {
-        // Ignore Payload errors in 404
-      }
-    }
-  }
-
   return (
     <>
-      <ClientNotFoundTracker path={urlPath} />
+      <ClientNotFoundTracker path="" />
       <Container className="relative py-24 flex flex-col items-center justify-center text-center min-h-[70vh] overflow-hidden">
         {/* Industrial Background Element */}
         <div className="absolute inset-0 -z-10 opacity-[0.03] pointer-events-none flex items-center justify-center">