- Fixed Genesys AudioHook serializer to always include the `parameters` field in
  protocol messages. The AudioHook protocol requires every message to carry a
  `parameters` object (even if empty), but `_create_message` omitted it when no
  parameters were provided. This caused clients that validate message structure
  (including the Genesys reference implementation) to reject `pong` and
  parameter-less `closed` responses, breaking server sequence tracking and
  preventing `outputVariables` from reaching the Architect flow.