Phase 1: YouTube tracker, auto-discovery and Most Subscribers board

- YouTube Data API v3 client with per-Pacific-day quota ledger and buckets
- Crawl planner: daily channel stats, WebSub ingest, uploads sync, tiered video refresh
- Automatic channel discovery: trending charts per market/category and featured-channel snowball
- Compliance: 30-day refresh-or-delete purge, feature flags for derived metrics
- Materialized leaderboards, channel pages with growth charts, Filament admin
- cPanel Git deployment via .cpanel.yml

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
