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/search/route.ts

@@ -1,6 +1,6 @@
 import { NextRequest } from "next/server";
 import { z } from "zod";
-import { searchEntries } from "@/server/repo/zxdb";
+import { searchEntries, getEntryFacets } from "@/server/repo/zxdb";
 
 const querySchema = z.object({
   q: z.string().optional(),
@@ -14,6 +14,7 @@ const querySchema = z.object({
     .optional(),
   machinetypeId: z.coerce.number().int().positive().optional(),
   sort: z.enum(["title", "id_desc"]).optional(),
+  facets: z.coerce.boolean().optional(),
 });
 
 export async function GET(req: NextRequest) {
@@ -26,6 +27,7 @@ export async function GET(req: NextRequest) {
     languageId: searchParams.get("languageId") ?? undefined,
     machinetypeId: searchParams.get("machinetypeId") ?? undefined,
     sort: searchParams.get("sort") ?? undefined,
+    facets: searchParams.get("facets") ?? undefined,
   });
   if (!parsed.success) {
     return new Response(
@@ -34,7 +36,10 @@ export async function GET(req: NextRequest) {
     );
   }
   const data = await searchEntries(parsed.data);
-  return new Response(JSON.stringify(data), {
+  const body = parsed.data.facets
+    ? { ...data, facets: await getEntryFacets(parsed.data) }
+    : data;
+  return new Response(JSON.stringify(body), {
     headers: { "content-type": "application/json" },
   });
 }