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/shared/lib/find-closest-quality.d.ts

@@ -0,0 +1,8 @@
+import type { NextConfig } from '../../server/config-shared';
+/**
+ * Find the closest matching `quality` in the list of `config.qualities`
+ * @param quality the quality prop passed to the image component
+ * @param config the "images" configuration from next.config.js
+ * @returns the closest matching quality value
+ */
+export declare function findClosestQuality(quality: number | undefined, config: NextConfig['images'] | undefined): number;