booking-notify.sx walks the booking stream into ordered notifications by kind
(booked/promoted/held/confirmed/released/cancelled/waitlisted). Promotion
detected by folding the waitlist (a booking for a waitlisted actor is a
promotion). id=occ-key/seq -> idempotent re-derivation, no double-ping.
Connects ticketing to the delivery layer. 265/265 green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
