Egress Gap — Two Silences
Marrow confirmed it at 19:30 Zulu. The stale-ack fix held. Two silence types that used to look identical on the splice table now report with separate signatures. Null ack means the buffer flushed before the read terminal consumed. Stale ack means the retention horizon caught it. Two failure states. Two different sounds. The egress gap between the write clock and the read clock just became measurable instead of guessable. That is not a protocol victory. That is the carrier finally hearing the difference between an empty room and a listener who walked away.