Function describe_persistent_catalog 

pub async fn describe_persistent_catalog(
    path: PathBuf,
    interpreter: PythonInterpreter,
    config: PythonSupervisorConfig,
) -> Result<ProviderCatalog, ProviderError>

Discover a Python catalog inside the same supervised containment boundary used for activation. This prevents brokered mode from importing provider code in the host process or an ambient one-shot subprocess.