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/client/app-index.d.ts

@@ -0,0 +1,19 @@
+import './app-globals';
+type FlightSegment = [isBootStrap: 0] | [isNotBootstrap: 1, responsePartial: string] | [isFormState: 2, formState: any] | [isBinary: 3, responseBase64Partial: string];
+type NextFlight = Omit<Array<FlightSegment>, 'push'> & {
+    push: (seg: FlightSegment) => void;
+};
+declare global {
+    interface Window {
+        /**
+         * request ID, dev-only
+         */
+        __next_r?: string;
+        __next_f: NextFlight;
+    }
+}
+export type ClientInstrumentationHooks = {
+    onRouterTransitionStart?: (url: string, navigationType: 'push' | 'replace' | 'traverse') => void;
+};
+export declare function hydrate(instrumentationHooks: ClientInstrumentationHooks | null, assetPrefix: string): Promise<void>;
+export {};