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/deep-freeze.d.ts

@@ -0,0 +1,10 @@
+import type { DeepReadonly } from './deep-readonly';
+/**
+ * Recursively freezes an object and all of its properties. This prevents the
+ * object from being modified at runtime. When the JS runtime is running in
+ * strict mode, any attempts to modify a frozen object will throw an error.
+ *
+ * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/freeze
+ * @param obj The object to freeze.
+ */
+export declare function deepFreeze<T extends object>(obj: T): DeepReadonly<T>;