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/zxdb/genres/[id]/GenreDetail.tsx

@@ -1,38 +1,20 @@
 "use client";
 
-import { useEffect, useMemo, useState } from "react";
+import Link from "next/link";
+import { useMemo, useState } from "react";
 
 type Item = { id: number; title: string; isXrated: number; machinetypeId: number | null; languageId: string | null };
 type Paged<T> = { items: T[]; page: number; pageSize: number; total: number };
 
-export default function GenreDetailClient({ id }: { id: number }) {
-  const [data, setData] = useState<Paged<Item> | null>(null);
-  const [loading, setLoading] = useState(false);
-  const [page, setPage] = useState(1);
-  const pageSize = 20;
-  const totalPages = useMemo(() => (data ? Math.max(1, Math.ceil(data.total / data.pageSize)) : 1), [data]);
-
-  async function load(p: number) {
-    setLoading(true);
-    try {
-      const res = await fetch(`/api/zxdb/genres/${id}?page=${p}&pageSize=${pageSize}`, { cache: "no-store" });
-      const json = (await res.json()) as Paged<Item>;
-      setData(json);
-    } finally {
-      setLoading(false);
-    }
-  }
-
-  useEffect(() => {
-    load(page);
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [page]);
+export default function GenreDetailClient({ id, initial }: { id: number; initial: Paged<Item> }) {
+  const [data] = useState<Paged<Item>>(initial);
+  const [page] = useState(1);
+  const totalPages = useMemo(() => Math.max(1, Math.ceil(data.total / data.pageSize)), [data]);
 
   return (
     <div className="container">
       <h1>Genre #{id}</h1>
-      {loading && <div>Loading…</div>}
-      {data && data.items.length === 0 && !loading && <div className="alert alert-warning">No entries.</div>}
+      {data && data.items.length === 0 && <div className="alert alert-warning">No entries.</div>}
       {data && data.items.length > 0 && (
         <div className="table-responsive">
           <table className="table table-striped table-hover align-middle">
@@ -48,7 +30,7 @@ export default function GenreDetailClient({ id }: { id: number }) {
               {data.items.map((it) => (
                 <tr key={it.id}>
                   <td>{it.id}</td>
-                  <td><a href={`/zxdb/entries/${it.id}`}>{it.title}</a></td>
+                  <td><Link href={`/zxdb/entries/${it.id}`}>{it.title}</Link></td>
                   <td>{it.machinetypeId ?? "-"}</td>
                   <td>{it.languageId ?? "-"}</td>
                 </tr>
@@ -59,9 +41,7 @@ export default function GenreDetailClient({ id }: { id: number }) {
       )}
 
       <div className="d-flex align-items-center gap-2 mt-2">
-        <button className="btn btn-outline-secondary" onClick={() => setPage((p) => Math.max(1, p - 1))} disabled={loading || page <= 1}>Prev</button>
-        <span>Page {data?.page ?? page} / {totalPages}</span>
-        <button className="btn btn-outline-secondary" onClick={() => setPage((p) => p + 1)} disabled={loading || (data ? data.page >= totalPages : false)}>Next</button>
+        <span>Page {data.page} / {totalPages}</span>
       </div>
     </div>
   );