feat: add premium Next.js scaffold to Domain_web

Bundle geoexport-premium (Docker, docs, Next.js) alongside the
working static site mirror; production VPS install still uses site/.

Co-authored-by: Cursor <cursoragent@cursor.com>

premium/next.config.ts

@@ -0,0 +1,7 @@
+import type { NextConfig } from "next";
+
+const nextConfig: NextConfig = {
+  /* config options here */
+};
+
+export default nextConfig;