How an async subagent's task ended or paused, as reported to the agent that started it.
A notification message carries it as notification metadata with source
"async_subagent"; read it with getNotificationMetadata(message)?.data.
additional_kwargs.deepagents_notification also carries it; that key is
deprecated.
This shape is experimental and subject to change.
The async subagent's name, as in the task's AsyncTask.agentName.
The subagent run that ended.
waiting means the subagent paused for input or approval; cancelled, that its run was cancelled on the server.
The task's ID (the subagent's thread).
