Function cancel_forest_plans 

async fn cancel_forest_plans(
    executor: &mut ExecutorConn,
    forest: &HashMap<String, TreeMeta>,
    _session_id: &str,
)

Cancel every real task tree owned by this turn before reporting the Pilot session interrupted. Dropping the Execute stream alone only detaches Pilot; Executor continues the plan (and synchronous tools such as run_command) unless its PlanRuntime receives an explicit cancel_plan request.