A consumer that was deleted with its module

A queue consumer removed along with the module it belonged to, and the queue that kept receiving messages.

the module was deleted in June. the consumer went with
it.

what did not: the producer, in a different module,
still dispatching to that queue.

  messages published, July:  41,208
  messages consumed:              0
  queue depth alert:        did not fire — the alert
                            is on oldest-message age,
                            and the queue was being
                            purged by a TTL nobody
                            remembered configuring.

A TTL on a queue turns an unconsumed backlog into silence, which is why the age alert did not fire — messages were expiring before they got old. The check that would have caught it is the one for events with no consumers, which had been converted into a failing build check in March and did not cover queues.