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/lib/server-action-request-meta.d.ts

@@ -0,0 +1,11 @@
+import type { IncomingMessage } from 'http';
+import type { BaseNextRequest } from '../base-http';
+import type { NextRequest } from '../web/exports';
+export declare function getServerActionRequestMetadata(req: IncomingMessage | BaseNextRequest | NextRequest): {
+    actionId: string | null;
+    isURLEncodedAction: boolean;
+    isMultipartAction: boolean;
+    isFetchAction: boolean;
+    isPossibleServerAction: boolean;
+};
+export declare function getIsPossibleServerAction(req: IncomingMessage | BaseNextRequest | NextRequest): boolean;