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/server/after/awaiter.d.ts

@@ -0,0 +1,29 @@
+/**
+ * Provides a `waitUntil` implementation which gathers promises to be awaited later (via {@link AwaiterMulti.awaiting}).
+ * Unlike a simple `Promise.all`, {@link AwaiterMulti} works recursively --
+ * if a promise passed to {@link AwaiterMulti.waitUntil} calls `waitUntil` again,
+ * that second promise will also be awaited.
+ */
+export declare class AwaiterMulti {
+    private promises;
+    private onError;
+    constructor({ onError }?: {
+        onError?: (error: unknown) => void;
+    });
+    waitUntil: (promise: Promise<unknown>) => void;
+    awaiting(): Promise<void>;
+}
+/**
+ * Like {@link AwaiterMulti}, but can only be awaited once.
+ * If {@link AwaiterOnce.waitUntil} is called after that, it will throw.
+ */
+export declare class AwaiterOnce {
+    private awaiter;
+    private done;
+    private pending;
+    constructor(options?: {
+        onError?: (error: unknown) => void;
+    });
+    waitUntil: (promise: Promise<unknown>) => void;
+    awaiting(): Promise<void>;
+}