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/get-page-files.d.ts

@@ -0,0 +1,14 @@
+export type BuildManifest = {
+    devFiles: readonly string[];
+    polyfillFiles: readonly string[];
+    lowPriorityFiles: readonly string[];
+    rootMainFiles: readonly string[];
+    rootMainFilesTree: {
+        [appRoute: string]: readonly string[];
+    };
+    pages: {
+        '/_app': readonly string[];
+        [page: string]: readonly string[];
+    };
+};
+export declare function getPageFiles(buildManifest: BuildManifest, page: string): readonly string[];