Isolate a pre-greeting clear from the next announcement

A control frame used to clear pre-greeting audio can leave the next required announcement marked unconfirmed even when it audibly plays. When the announcement and clear share a transition, correlate the announcement's text, audio, and stop frames after the clear before deciding it remains owed. Also keep the clear's playback epoch separate from newly queued speech. This is a qualified race hypothesis: without the context-binding timestamp, a false receipt and a missed completion flag may be parallel symptoms rather than one proven causal chain.

Applies when: A streamed voice workflow clears probe audio immediately before a required announcement. Keywords: voice announcement replay clear frame epoch receipt context audio stop