Function new_auto_manager 

pub fn new_auto_manager(
    goos: &str,
    cfg: ClusterConfig,
    profile_name: String,
) -> Box<dyn DriverTrait>

Port of auto.newAutoManager: resolves goos to a concrete driver (colima on darwin, k3d elsewhere) and returns it directly — the returned value’s Name() reports the resolved driver, not “auto”.