Building one page that looks like a page the course already has — copy the model page with `duplicate_scene`, then rewrite the copy's words with one `patch_stage` op per content slot. Use when a new page has to inherit an existing page's design, whether the model page came from an imported deck or the course wrote it earlier. Not for revising a page that is already the page you want (that is `pro-editing`), and not for the course-level work of cataloguing layouts and assigning one per outline entry (that is `style-clone`).