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/server/serve-static.d.ts

@@ -0,0 +1,5 @@
+import type { IncomingMessage, ServerResponse } from 'http';
+import send from 'next/dist/compiled/send';
+export declare function serveStatic(req: IncomingMessage, res: ServerResponse, path: string, opts?: Parameters<typeof send>[2]): Promise<void>;
+export declare const getContentType: (extWithoutDot: string) => string | null;
+export declare const getExtension: (contentType: string) => string | null;