Emitted by the supervisor when a delegated sub-agent's result has been folded back into the
conversation — the counterpart of DelegationSpawned, and the only durable record that the
return happened at all. A child's own trace ends with its operation; that it reported to someone
is knowable only from the supervisor's side, so without this the delegation reads as a one-way
spawn even though the runtime genuinely returns a value.
Emitted by the supervisor when a delegated sub-agent's result has been folded back into the conversation — the counterpart of DelegationSpawned, and the only durable record that the return happened at all. A child's own trace ends with its operation; that it reported to someone is knowable only from the supervisor's side, so without this the delegation reads as a one-way spawn even though the runtime genuinely returns a value.