Function assemble_preparation_only_engine_registration 

pub fn assemble_preparation_only_engine_registration(
    config: PreparationOnlyEngineRegistrationConfig,
) -> Result<EngineRegistration, RuntimeConfigError>

Assemble one preparation-only provider registration.

This is the preparation counterpart of assemble_executable_engine_registration. It deliberately cannot manufacture an execution bridge or a scheduled witness.

Errors

Returns RuntimeConfigError if the descriptor contains empty or duplicate storage classes, or if its default storage class is not listed in the supported storage classes.