1-based delivery attempt. Present for 'queue' (from IJob.attempts)
and 'scheduler' (from ScheduledJob.attempts); ABSENT for
'messaging' and 'websocket'. Absent means "this ingress cannot tell
you" — never "first try": brokers redeliver and none tracks a delivery
count, so a fabricated 1 would lie on a fifth redelivery.
Usage
import { type IngressContext } from "common/src/index.ts";