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/escalade/index.d.mts

@@ -0,0 +1,11 @@
+type Promisable<T> = T | Promise<T>;
+
+export type Callback = (
+	directory: string,
+	files: string[],
+) => Promisable<string | false | void>;
+
+export default function (
+	directory: string,
+	callback: Callback,
+): Promise<string | void>;