docs(campaign): define broker redelivery evidence

docs/EXAMPLE_CAMPAIGNS_AND_RELEASE_CHECKLIST.md

@@ -65,6 +65,13 @@ Before tagging a campaign release:
 - Treat the task-process restart proof separately from the still-open
   Redis/Celery broker redelivery and daemon-supervision check; the coverage
   projection must keep `celery_broker_redelivery` false.
+- Run `dev/mail-testbed/run_celery_redelivery_acceptance.py` as a separate
+  destructive worker-loss check. Retain its bounded evidence only when the same
+  broker task is observed at both workers, the durable state is
+  `outcome_unknown`, broker queue/unacked counts are zero, and the controlled
+  SMTP endpoint observed one connection and one DATA transaction. This closes
+  local Redis/Celery redelivery coverage, while production supervisor and
+  target-provider coverage remain false until separately tested.
 - Confirm reusable mail profile selection is revalidated after campaign owner
   transfer.
 - Confirm every inline SMTP/IMAP field is rejected on import/write, omitted