Stopping the engine cancels the context every http and slack request is
sent with. An attempt cut off that way was recorded as failed, which for
a target with no retries, or on a last retry, ended the delivery failed
and nothing sent it again.
The shared retry core now records nothing for a failed attempt when the
engine's context is cancelled: no result, no circuit breaker outcome, no
status change, no count in the attempt metrics. The delivery stays
pending or retrying and startup recovery sends it again. A target's own
timeout is still a failed attempt. The README says what happens to an
attempt in flight at a stop and no longer claims every attempt is
recorded.
Model: opus-5-5
sneak