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/lib/streaming-metadata.d.ts

@@ -0,0 +1,5 @@
+import type { BaseNextRequest } from '../base-http';
+export declare function shouldServeStreamingMetadata(userAgent: string, htmlLimitedBots: string | undefined): boolean;
+export declare function isHtmlBotRequest(req: {
+    headers: BaseNextRequest['headers'];
+}): boolean;