- Add chess piece upload UI to admin/branding.php (12 slots: white + black)
- Fix loadPieceImages race condition in board renderer
- Add tournament system module (Swiss, knockout, arena)
- Add promo banner (1m×3m display) and video assets
- Add 2-min display video script
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>