The run the turn belongs to.
The turn's number in its run, in arrival order.
The turn's stable id, <runId>:<seq>.
Wall-clock milliseconds when the turn was written.
The turn's transcribed text.
Optional speakerWho spoke, when the session can tell.
Optional startWhere the turn starts on the session's audio clock, when the transcriber gave one.
Optional endWhere the turn ends on the same clock, when the transcriber gave one.
A transcript turn a listen session wrote.
turnIdis<runId>:<seq>, assigned by the sink in arrival order.