Restore the app files (prior commit mis-scoped its tar)

Co-Authored-By: Claude Opus 4.8 <[email protected]>

frontend/src/pages/PostsPage.tsx

@@ -0,0 +1,20 @@
+import { getPosts } from '../api';
+import { useAsync } from '../lib/useAsync';
+import PostCard from '../components/PostCard';
+
+export default function PostsPage() {
+  const { data: posts, loading } = useAsync(() => getPosts(), []);
+  const list = posts ?? [];
+
+  return (
+    <div className="mx-auto max-w-5xl">
+      <h1 className="mb-6 text-3xl font-bold md:text-4xl">Archive</h1>
+      <p className="mb-10 text-lg text-primary-700">Every post, newest first.</p>
+      {loading && <p className="text-primary-500">Loading…</p>}
+      <div className="grid grid-cols-1 gap-6 md:grid-cols-2">
+        {list.map((post) => <PostCard key={post.slug} post={post} />)}
+      </div>
+      {!loading && list.length === 0 && <p className="text-primary-500">No posts yet.</p>}
+    </div>
+  );
+}