Mirrors the Phase 6 instrumentation already on the replay side
(processMatches) onto the walker's Delete dispatch. Every walker
dispatch now bumps S3LifecycleDispatchCounter with the resolved
outcome (or TRANSPORT_ERROR / NIL_RESPONSE for the failure paths) so
streaming, daily_replay's replay drain, and daily_replay's walker
share a single per-(bucket, kind, outcome) counter view.
Lands together with the rest of Phase 4b — no new metric, just an
extra observation site for the existing one.
Chris Lu
87f29874c3