untell checks a reply is still in force before it waits again, and hear_replies resolves each reply on its own, so one refused
resolution neither retells a reply nobody can answer nor holds the rest of its batch. Tests: out-of-force retell, a reply reaching an
idle session with no chat pending, and a reply waiting across a read while a line is not echoed (a stalled child).
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>