AgentSlot.telemetry was written only by the Agent.Initialize handler, so every
CommittedSnapshot carried warm-up telemetry labelled as boundary k while each
AgentCommitResult.telemetry was validated and dropped. The commit result is now
stored on the slot beside the committed step, and the media test asserts that
published telemetry advances across boundaries instead of merely being nonzero.
A refused snapshot is recorded and sequenced like a refused descriptor revision,
because the repair path exists for the consumer that did not receive it; the
sequence advances with the value rather than with the delivery, so two snapshots
can never share one. The query service counts an answer it could not deliver
rather than discarding the result, and an unreadable event batch is distinct
from the end of the stream.
6bf5687aca