GateStep.validate() reports non-string options as an error, but then -- when on_reject is 'abort'/'retry' -- still runs the reject-choice check 'any(o.lower() in ... for o in options)'. For a non-string option (e.g. options: [123]) o.lower() raised AttributeError, which escaped validate() and broke validate_workflow's documented 'return a list of errors, never raise' contract. Guard the check so it only runs when every option is a string (the non-string case is already reported above).
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>