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/bfcache.d.ts

@@ -0,0 +1,27 @@
+import type { FlightRouterState } from '../../shared/lib/app-router-types';
+export type RouterBFCacheEntry = {
+    tree: FlightRouterState;
+    stateKey: string;
+    next: RouterBFCacheEntry | null;
+};
+/**
+ * Keeps track of the most recent N trees (FlightRouterStates) that were active
+ * at a certain segment level. E.g. for a segment "/a/b/[param]", this hook
+ * tracks the last N param values that the router rendered for N.
+ *
+ * The result of this hook precisely determines the number and order of
+ * trees that are rendered in parallel at their segment level.
+ *
+ * The purpose of this cache is to we can preserve the React and DOM state of
+ * some number of inactive trees, by rendering them in an <Activity> boundary.
+ * That means it would not make sense for the the lifetime of the cache to be
+ * any longer than the lifetime of the React tree; e.g. if the hook were
+ * unmounted, then the React tree would be, too. So, we use React state to
+ * manage it.
+ *
+ * Note that we don't store the RSC data for the cache entries in this hook —
+ * the data for inactive segments is stored in the parent CacheNode, which
+ * *does* have a longer lifetime than the React tree. This hook only determines
+ * which of those trees should have their *state* preserved, by <Activity>.
+ */
+export declare function useRouterBFCache(activeTree: FlightRouterState, activeStateKey: string): RouterBFCacheEntry;