Function serve 

pub async fn serve<S: WorkflowStore + Clone + 'static>(
    bind_addr: &str,
    state: EngineState<S>,
) -> Result<()>

Bind a TCP listener on bind_addr and serve the composed app.

Convenience wrapper that composes EngineState into an axum::Router via build_app and hands off to bind_and_serve. Used by the standalone assay-engine binary.