Function run_with_policy 

pub async fn run_with_policy(
    state: &AppState,
    tab_id: String,
    block_id: String,
    policy: Policy,
) -> (Result<Value, String>, Option<TeardownReport>)

run with the teardown policy for the block (self_quit passes Policy::quit()). Returns the saga’s result and the teardown’s report; the report is there whenever the teardown ran, even if the close then failed, and None only when the close failed before it.