Function run_streaming 

fn run_streaming(
    cmd: Command,
    label: &str,
    stdin_payload: &str,
    verbose: bool,
    color: Style,
    turn_timeout: Duration,
    interrupted: Arc<AtomicBool>,
    on_event: impl FnMut(&Value) -> Result<()>,
) -> Result<(ExitStatus, String)>

Spawn cmd with stdin_payload piped in, stream stdout line-by-line, call on_event for each JSON line (echoing raw lines to stderr when verbose), and return the exit status plus captured stderr.