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/route-definitions/route-definition.d.ts

@@ -0,0 +1,16 @@
+import type { RouteKind } from '../route-kind';
+export interface RouteDefinition<K extends RouteKind = RouteKind> {
+    readonly kind: K;
+    readonly bundlePath: string;
+    readonly filename: string;
+    /**
+     * Describes the pathname including all internal modifiers such as
+     * intercepting routes, parallel routes and route/page suffixes that are not
+     * part of the pathname.
+     */
+    readonly page: string;
+    /**
+     * The pathname (including dynamic placeholders) for a route to resolve.
+     */
+    readonly pathname: string;
+}