fn main() {
    // Consumer decides logging; library remains silent by default.
    #[cfg(feature = "tracing")]
    {
        use tracing::{info, Level};
        use tracing_subscriber::FmtSubscriber;
        let subscriber = FmtSubscriber::builder()
            .with_max_level(Level::INFO)
            .finish();
        let _ = tracing::subscriber::set_global_default(subscriber);
        info!("starting simulation");
    }

    let mut p = medicallib_rust::Patient::new("trace-demo")
        .unwrap()
        .initialize_default()
        .with_lungs();
    p.update(0.2);
    println!("{}", p.patient_summary());
}