Steer Run

Send a mid-run steering message to a live agent stage of a running run: the stage stage names, or the run's one live agent stage. Without interrupt, the text is guidance for the stage's session, run as a follow-up turn once its current answer is reached. With interrupt=true, the stage's current model turn (the model request and the tool calls it is running) is stopped first, the session is kept, and the text is the stage's next input. The control is forwarded to the run's worker, and the worker's answer is this response: 202 with outcome: delivered (and the stage's label) once the worker delivered it, 409 with the refusal's code when the worker or Petri refused it, and 202 with outcome: pending when the worker gave no answer within the wait (5 s). A refused control is also a run.notice record on the run's event stream under the same code (steer_refused, no_live_turn, no_such_stage, interrupt_refused).