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/image-blur-svg.d.ts

@@ -0,0 +1,11 @@
+/**
+ * A shared function, used on both client and server, to generate a SVG blur placeholder.
+ */
+export declare function getImageBlurSvg({ widthInt, heightInt, blurWidth, blurHeight, blurDataURL, objectFit, }: {
+    widthInt?: number;
+    heightInt?: number;
+    blurWidth?: number;
+    blurHeight?: number;
+    blurDataURL: string;
+    objectFit?: string;
+}): string;