chore: commit pending ZXDB explorer changes prior to index perf work

Context
- Housekeeping commit to capture all current ZXDB Explorer work before index-page performance optimizations.

Includes
- Server-rendered entry detail page with ISR and parallelized DB queries.
- Node runtime for ZXDB API routes and params validation updates for Next 15.
- ZXDB repository extensions (facets, label queries, category queries).
- Cross-linking and Link-based prefetch across ZXDB UI.
- Cache headers on low-churn list APIs.

Notes
- Follow-up commit will focus specifically on speeding up index pages via SSR initial data and ISR.

Signed-off-by: Junie@lucy.xalior.com

src/app/api/zxdb/genres/route.ts

@@ -3,7 +3,10 @@ import { listGenres } from "@/server/repo/zxdb";
 export async function GET() {
   const data = await listGenres();
   return new Response(JSON.stringify({ items: data }), {
-    headers: { "content-type": "application/json", "cache-control": "no-store" },
+    headers: {
+      "content-type": "application/json",
+      "cache-control": "public, max-age=0, s-maxage=3600, stale-while-revalidate=86400",
+    },
   });
 }