Function get_power_transition 

pub async fn get_power_transition(
    infra: &InfraContext<'_>,
    token: &str,
    transition_id: &str,
) -> Result<TransitionResponse, Error>

Fetch the current snapshot of a PCS power transition by id. The CLI’s poll loop calls this every few seconds after apply_power returned the transition id.

Authorization: the caller must have group-access to every xname listed in the transition’s tasks. An admin token short-circuits the check. A transition with no tasks (an unusual edge case the backend can in principle return) is allowed through; the response contains no xnames the caller didn’t already supply.