Rewrite as a Spring Boot app on the Bennett platform

Restores the real backend lost with Supabase (posts, authors, comments, subscriptions, admin) in
Postgres, seeds the existing markdown posts, and rebuilds the site as a Vite/React SPA served by
Spring — keeping the original styling (serif + tan accent) and content.

frontend/src/components/PostCard.tsx

@@ -0,0 +1,41 @@
+import { Link } from 'react-router-dom';
+import { format } from 'date-fns';
+import type { PostSummary } from '../types';
+
+export default function PostCard({ post }: { post: PostSummary }) {
+  return (
+    <article className="card transition-shadow duration-200 hover:shadow-md">
+      {post.coverImage && (
+        <div className="relative mb-4 h-48 w-full overflow-hidden rounded-md">
+          <img src={post.coverImage} alt={post.title} className="h-full w-full object-cover" />
+        </div>
+      )}
+      <h2 className="mb-2 text-xl font-bold">
+        <Link to={`/posts/${post.slug}`} className="hover:text-accent-dark">{post.title}</Link>
+      </h2>
+      <div className="mb-2 flex items-center text-sm text-primary-500">
+        <span>{post.author}</span>
+        <span className="mx-2">•</span>
+        <time dateTime={post.date}>{format(new Date(post.date), 'MMMM d, yyyy')}</time>
+      </div>
+      <p className="mb-4 text-primary-600">{post.excerpt}</p>
+      <div className="mb-4 flex flex-wrap gap-2">
+        {post.tags.map((tag) => (
+          <Link
+            key={tag}
+            to={`/tags/${encodeURIComponent(tag)}`}
+            className="rounded-md bg-primary-100 px-2 py-1 text-xs text-primary-600 no-underline hover:bg-primary-200"
+          >
+            {tag}
+          </Link>
+        ))}
+      </div>
+      <Link to={`/posts/${post.slug}`} className="inline-flex items-center text-accent-dark hover:text-accent">
+        Read more
+        <svg xmlns="http://www.w3.org/2000/svg" className="ml-1 h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M14 5l7 7m0 0l-7 7m7-7H3" />
+        </svg>
+      </Link>
+    </article>
+  );
+}