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/lib/generate-interception-routes-rewrites.d.ts

@@ -0,0 +1,4 @@
+import type { Rewrite } from './load-custom-routes';
+import type { DeepReadonly } from '../shared/lib/deep-readonly';
+export declare function generateInterceptionRoutesRewrites(appPaths: string[], basePath?: string): Rewrite[];
+export declare function isInterceptionRouteRewrite(route: DeepReadonly<Rewrite>): boolean;