fix: run startup scrape only when database is empty

Restores the startup scrape removed in deb8e41, gated on
getParkDayCount() < 50 so warm restarts don't hammer the API.
Cold containers (e.g. after the volume mount fix) populate
immediately instead of waiting up to 24h for tier-4 cron.

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

backend/src/services/scheduler.ts

@@ -1,5 +1,6 @@
 import cron from "node-cron";
 import { scrapeToday, scrapeCurrentMonth, scrapeUpcomingMonths, scrapeFullYear } from "./scraper";
+import { getParkDayCount } from "../db/queries";
 
 let initialized = false;
 
@@ -36,4 +37,18 @@ export function startScheduler(): void {
   console.log("  tier-2: current month — every 6h");
   console.log("  tier-3: upcoming     — 3 AM + 3 PM");
   console.log("  tier-4: full year    — 3 AM daily");
+
+  const existingRows = getParkDayCount();
+  if (existingRows < 50) {
+    console.log(`[scheduler] DB has ${existingRows} rows — running startup scrape`);
+    scrapeToday()
+      .then((r) => {
+        console.log(`[scheduler] startup today: ${r.fetched} fetched, ${r.updated} updated, ${r.errors} errors`);
+        return scrapeFullYear();
+      })
+      .then((r) => console.log(`[scheduler] startup full-year: ${r.fetched} fetched, ${r.skipped} skipped, ${r.errors} errors`))
+      .catch((err) => console.error("[scheduler] startup scrape error:", err));
+  } else {
+    console.log(`[scheduler] DB has ${existingRows} rows — skipping startup scrape, relying on cron`);
+  }
 }