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/components/navigation-devtools.d.ts

@@ -0,0 +1,12 @@
+import type { FlightRouterState } from '../../shared/lib/app-router-types';
+import type { Params } from '../../server/request/params';
+import { type NavigationPromises } from '../../shared/lib/hooks-client-context.shared-runtime';
+/**
+ * Creates instrumented navigation promises for the root app-router.
+ */
+export declare function createRootNavigationPromises(tree: FlightRouterState, pathname: string, searchParams: URLSearchParams, pathParams: Params): NavigationPromises | null;
+/**
+ * Creates merged navigation promises for nested layouts.
+ * Merges parent promises with layout-specific segment promises.
+ */
+export declare function createNestedLayoutNavigationPromises(tree: FlightRouterState, parentNavPromises: NavigationPromises | null): NavigationPromises | null;