events: booking lifecycle notifications + 11 tests

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>

lib/events/conformance.conf

@@ -26,6 +26,7 @@ PRELOADS=(
   lib/persist/concurrency.sx
   lib/persist/api.sx
   lib/events/booking.sx
+  lib/events/booking-notify.sx
   lib/events/ticket.sx
   lib/guest/lex.sx
   lib/guest/reflective/env.sx
@@ -49,6 +50,7 @@ SUITES=(
   "availability:lib/events/tests/availability.sx:(ev-availability-tests-run!)"
   "api:lib/events/tests/api.sx:(ev-api-tests-run!)"
   "booking:lib/events/tests/booking.sx:(ev-booking-tests-run!)"
+  "booking-notify:lib/events/tests/booking-notify.sx:(ev-booking-notify-tests-run!)"
   "ticket:lib/events/tests/ticket.sx:(ev-ticket-tests-run!)"
   "notify:lib/events/tests/notify.sx:(ev-notify-tests-run!)"
   "reminders:lib/events/tests/reminders.sx:(ev-reminders-tests-run!)"