Function with_slow_future_monitor

pub async fn with_slow_future_monitor<F, C>(
    future: F,
    threshold: Duration,
    callback: C,
) -> F::Output
where
    F: Future,
    C: FnOnce(),

Wraps a future with slow/stuck detection using tokio::select!

This implementation races the future against a timer. If the timer expires first, the callback is executed (exactly once) but the future continues to run. This approach can detect stuck futures that never wake their waker.