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/@tailwindcss/postcss/dist/index.d.ts

@@ -0,0 +1,25 @@
+import { PluginCreator } from 'postcss';
+
+type PluginOptions = {
+    /**
+     * The base directory to scan for class candidates.
+     *
+     * Defaults to the current working directory.
+     */
+    base?: string;
+    /**
+     * Optimize and minify the output CSS.
+     */
+    optimize?: boolean | {
+        minify?: boolean;
+    };
+    /**
+     * Enable or disable asset URL rewriting.
+     *
+     * Defaults to `true`.
+     */
+    transformAssetUrls?: boolean;
+};
+declare const _default: PluginCreator<PluginOptions>;
+
+export = _default;