Function task_with_timeout 

pub fn task_with_timeout<M, F>(timeout: Duration, f: F, on_timeout: M) -> Cmd<M>
where
    M: Send + 'static,
    F: FnOnce(CancellationToken) -> M + Send + 'static,

Create a Cmd::Task that enforces a cooperative timeout.

The worker closure receives a CancellationToken and must honor it for timely timeout teardown. On timeout, the runtime requests cancellation and returns on_timeout; any late worker result is discarded.