Function pause_run_api 

pub fn pause_run_api(
    corpus: &str,
    service: &str,
    actor: Actor,
    pool: &State<DbPool>,
) -> Result<Json<RunControlDto>, Status>

Pause a run — block every in-progress task (status >= 0) of a (corpus, service) so the dispatcher stops leasing them. The agent twin of the report screen’s “Pause run” button. Token-gated via the Actor guard; 404 on an unknown corpus/service. Returns the count blocked. Reversible with the resume twin.