PendingTurn
dataclass #
A turn the protocol expects this agent to take.
triggering_envelope_id names the envelope that put the turn on the agent — typically the previous speaker's send. None if no envelope drove the expectation (e.g. fresh channel where the expected speaker is the creator with nothing yet posted). expected_at is when the turn became theirs (the triggering envelope's created_at, or the current hub clock if no trigger envelope is available).