`POST` `/attempt/stop`

Attempt Stop

Request Body (`AttemptStopRequest`)

Field	Type	Required	Description
`group_id`	`string`	Yes	—
`idempotency_key`	`string`	No	Idempotency key — replays the prior call; on the ack, set to the server-minted soft key to perform/reject a staged stop
`soft`	`boolean`	No	Stage the stop (record the intent without cancelling) — for composing a stop into a dormant benchmark scenario; accept performs it
`accept`	`boolean`	No	Ack: True performs the staged stop, False discards. Only meaningful with idempotency_key

Field	Type	Required	Description
`success`	`boolean`	Yes	—
`idempotency_key`	`string`	No	Server-minted soft-call key (audit call_id). On a soft propose, echo this back with accept to perform/reject the staged stop.