feat(api): hourly catalog backfill for decoded-but-unfetched vehicles

prefetch was reactive-only (on decode) and processInit read top-level
categories straight from DB, so a vehicle decoded but never viewed got
no catalog. Add a production-only sweep so no decoded vehicle is left
without catalog data.

- processInit self-seeds top categories via getCategoryTree when DB has
  none (fetches+inserts top groups from PL24/PSA/EMEX), closing the
  never-viewed gap for both reactive and backfill paths
- new backfill-scan job + hourly cron: phase 1 queues decoded vehicles
  with zero parts, phase 2 rolling createdAt-cursor rescan of all decoded
  vehicles (prefetch-init is idempotent → gap-fills partial ones)
- guardrails: skip wave if queue backlog > 1000, per-source cooldown,
  business-hours window (isWithinTimeWindow), batch <=20, in-flight guard
- PRODUCTION ONLY: gated on NODE_ENV both at cron registration and in
  processBackfillScan; dev has a separate DB and must not scrape

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/api/src/jobs/prefetch-utils.ts

@@ -24,22 +24,34 @@ export async function checkCooldown(redis: RedisService, source: string): Promis
   }
 }
 
-/**
- * Check PL24 business hours (09:00–18:00 Europe/Istanbul).
- * Throws RateLimitError with delay until next 09:00 if outside window.
- */
-export function checkTimeWindow(source: string): void {
-  if (source !== "pl24" && source !== "parts-catalogs") return;
-
+/** Current hour (0–23) in Europe/Istanbul. */
+function currentIstanbulHour(): number {
   const hourStr = new Intl.DateTimeFormat("en-US", {
     timeZone: "Europe/Istanbul",
     hour: "numeric",
     hour12: false,
   }).format(new Date());
-  const h = Number.parseInt(hourStr, 10);
+  return Number.parseInt(hourStr, 10);
+}
 
+/**
+ * Whether `source` may be scraped right now.
+ * PL24 → 09:00–18:00, parts-catalogs → 09:00–19:00 (Europe/Istanbul).
+ * EMEX and everything else have no window (always true).
+ */
+export function isWithinTimeWindow(source: string): boolean {
+  if (source !== "pl24" && source !== "parts-catalogs") return true;
+  const h = currentIstanbulHour();
   const endHour = source === "parts-catalogs" ? 19 : 18;
-  if (h < 9 || h >= endHour) {
+  return h >= 9 && h < endHour;
+}
+
+/**
+ * Check PL24 business hours (09:00–18:00 Europe/Istanbul).
+ * Throws RateLimitError with delay until next 09:00 if outside window.
+ */
+export function checkTimeWindow(source: string): void {
+  if (!isWithinTimeWindow(source)) {
     throw new RateLimitError(msUntilNext9AM());
   }
 }