'sync:push', 'codegen', 'migrate', etc.
OptionaldataOptionalerrorsOptionalversionMJ_CLI_RESULT_VERSION. Optional on construction — SerializeResult
stamps it — so it is always present on the wire and never a burden at a call site.
Optionalwarnings
Universal result shape every plugin returns (plan D6). Command-specific detail goes in the typed MJCLIResult.data field; failures always go in MJCLIResult.errors with full detail (not just a count).