Add registry kind indexes and entity pages.

CONTENT-WP-0002-T02 reads kinds from each snapshot and serves both example dataspaces without oncology imports.

Assistant: grok
Assistant-Session: 01a1346c-fdff-7741-b1af-b7283661554b

ui/components/KindIndex.tsx

@@ -0,0 +1,15 @@
+import { RecordBrowser } from "@/components/RecordBrowser";
+import { PageHeader } from "@/components/PageHeader";
+import type { KindView } from "@/lib/catalog";
+
+/** Kind directory. The heading and rows come from the snapshot kind registry. */
+export function KindIndex({ kind }: { kind: KindView }) {
+  const count = kind.rows.length;
+  const lede = count === 1 ? `1 record in ${kind.dataspaceTitle}.` : `${count} records in ${kind.dataspaceTitle}.`;
+  return (
+    <>
+      <PageHeader kicker={kind.dataspaceTitle} title={kind.plural} lede={lede} />
+      <RecordBrowser rows={kind.rows} />
+    </>
+  );
+}