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/esm/client/route-announcer.js

@@ -0,0 +1,56 @@
+import { jsx as _jsx } from "react/jsx-runtime";
+import React from 'react';
+import { useRouter } from './router';
+const nextjsRouteAnnouncerStyles = {
+    border: 0,
+    clip: 'rect(0 0 0 0)',
+    height: '1px',
+    margin: '-1px',
+    overflow: 'hidden',
+    padding: 0,
+    position: 'absolute',
+    top: 0,
+    width: '1px',
+    // https://medium.com/@jessebeach/beware-smushed-off-screen-accessible-text-5952a4c2cbfe
+    whiteSpace: 'nowrap',
+    wordWrap: 'normal'
+};
+export const RouteAnnouncer = ()=>{
+    const { asPath } = useRouter();
+    const [routeAnnouncement, setRouteAnnouncement] = React.useState('');
+    // Only announce the path change, but not for the first load because screen
+    // reader will do that automatically.
+    const previouslyLoadedPath = React.useRef(asPath);
+    // Every time the path changes, announce the new page’s title following this
+    // priority: first the document title (from head), otherwise the first h1, or
+    // if none of these exist, then the pathname from the URL. This methodology is
+    // inspired by Marcy Sutton’s accessible client routing user testing. More
+    // information can be found here:
+    // https://www.gatsbyjs.com/blog/2019-07-11-user-testing-accessible-client-routing/
+    React.useEffect(()=>{
+        // If the path hasn't change, we do nothing.
+        if (previouslyLoadedPath.current === asPath) return;
+        previouslyLoadedPath.current = asPath;
+        if (document.title) {
+            setRouteAnnouncement(document.title);
+        } else {
+            const pageHeader = document.querySelector('h1');
+            const content = pageHeader?.innerText ?? pageHeader?.textContent;
+            setRouteAnnouncement(content || asPath);
+        }
+    }, // TODO: switch to pathname + query object of dynamic route requirements
+    [
+        asPath
+    ]);
+    return /*#__PURE__*/ _jsx("p", {
+        "aria-live": "assertive" // Make the announcement immediately.
+        ,
+        id: "__next-route-announcer__",
+        role: "alert",
+        style: nextjsRouteAnnouncerStyles,
+        children: routeAnnouncement
+    });
+};
+export default RouteAnnouncer;
+
+//# sourceMappingURL=route-announcer.js.map