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/app-render/make-get-server-inserted-html.d.ts

@@ -0,0 +1,9 @@
+import React, { type JSX } from 'react';
+import type { ClientTraceDataEntry } from '../lib/trace/tracer';
+export declare function makeGetServerInsertedHTML({ polyfills, renderServerInsertedHTML, serverCapturedErrors, tracingMetadata, basePath, }: {
+    polyfills: JSX.IntrinsicElements['script'][];
+    renderServerInsertedHTML: () => React.ReactNode;
+    tracingMetadata: ClientTraceDataEntry[] | undefined;
+    serverCapturedErrors: Array<unknown>;
+    basePath: string;
+}): () => Promise<string>;