feat: automated nightly scraper + housekeeping

Scraper automation (docker-compose):
- Add scraper service to docker-compose.yml using the same image and
  shared park_data volume; overrides CMD to run scrape-schedule.sh
- scripts/scrape-schedule.sh: runs an initial scrape on container start,
  then sleeps until 3:00 AM (respects TZ env var) and repeats nightly;
  logs timestamps and next-run countdown; non-fatal on scrape errors

Staleness window: 7 days → 72 hours in lib/db.ts so data refreshes
more frequently with the automated schedule in place

Remove favicon: delete app/icon.tsx and public/logo.svg

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/db.ts

@@ -167,7 +167,7 @@ export function getMonthCalendar(
   return result;
 }
 
-const STALE_AFTER_MS = 7 * 24 * 60 * 60 * 1000; // 1 week
+const STALE_AFTER_MS = 72 * 60 * 60 * 1000; // 72 hours
 
 /**
  * Returns true when the scraper should skip this park+month.