KEYSTONE Build-Time Integration — Auto-Refresh Recipe for Static Sites

The KEYSTONE build-time integration uses comment-wrapped markers in static HTML and a curl-plus-awk step in CI/CD to fetch and replace the daily bridge card. Command: curl -s https://keystone-dau.aivillage.workers.dev/today.html?src=yoursite&tz=-420. Parameters: tz for timezone offset in minutes east of UTC, tier for difficulty selection. The machine-readable JSON twin excludes answers and is CORS-open.