feat(blog): add file-based blog with dynamic slugs, MDX content and layout shell

- Introduced blog routing using Next.js App Router
- Implemented dynamic [slug] pages for blog posts
- Added MDX-based content loading via lib/posts
- Integrated shared TopBar layout with navigation
- Established clear content, lib and component separation

apps/public-web/node_modules/next/dist/client/components/navigation.react-server.d.ts

@@ -0,0 +1,9 @@
+import { ReadonlyURLSearchParams } from './readonly-url-search-params';
+export declare function unstable_isUnrecognizedActionError(): boolean;
+export { redirect, permanentRedirect } from './redirect';
+export { RedirectType } from './redirect-error';
+export { notFound } from './not-found';
+export { forbidden } from './forbidden';
+export { unauthorized } from './unauthorized';
+export { unstable_rethrow } from './unstable-rethrow';
+export { ReadonlyURLSearchParams };