Poll a message

One message's status and every reply the agent has sent since it landed.

Requires the agent:message scope.

Response. ```json { "message": { "requestId": "f2a283fd-…", "status": "replied", "done": true, "text": "What did we ship this week?", "sentAt": 1789851456304, "replies": [{ "text": "Three things shipped: …", "at": 1789851468121 }], "backgroundTasks": [] } }

`status` is `queued`, `running`, `replied` or `failed` (with a `failure` message; re-send with a new client id). `replied` means the agent answered and finished the turn. The agent may answer in more than one bubble, and it often posts progress while it works, so `replies` can fill while the status is still `running`. It is a list, oldest first, holding the latest five bubbles. `interrupted: true` means a later message stopped this turn before it finished.

Long research, such as building a list of 50 companies, runs as a background task: the agent replies that it has started, its turn ends with `status: "replied"`, and the research carries on. `backgroundTasks` lists each task the message started with its `id`, `label`, `state` (`running`, `done`, `failed` or `stopped`), `startedAt` and `endedAt`. A task is `done` once the agent has checked and saved its results and reported them, and that report joins `replies` (the latest ten bubbles). `done` on the message is `true` only when the turn has ended and no task is still running, so wait for `done`, not for `replied`. `404` for an unknown id, a colleague's dashboard turn, or another account's message.