Preview feature: Use the optional `preview` field on options when presenting concrete artifacts that users need to visually compare: - ASCII mockups of UI layouts or components - Code snippets showing different implementations - Diagram variations - Configuration examples Preview content is rendered as markdown in a monospace box. Multi-line text with newlines is supported. When any option has a preview, the UI switches to a side-by-side layout with a vertical option list on the left and preview on the right. Do not use previews for simple preference questions where labels and descriptions suffice. Note: previews are only supported for single-select questions (not multiSelect).