The siege can now auto-open registration on scheduled days/time instead of only
manual /csphase. Schedule is context-owned state (like owner), persisted across
restarts via the same config-JSON path. New GM command /csschedule sets/views/clears
it (e.g. /csschedule Sunday 20:00, UTC). +2 unit tests (11 total).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
ac6700a356