Themes
AI themes are private StoreTheme drafts. Create with POST /api/v1/themes, mutate sections/pages incrementally, preview with ?preview=true&previewThemeId=…, then publish with themes:publish.
Themes reference real product IDs — they never duplicate price or inventory. System templates Aura, TechNova, and Paper remain available in the merchant Themes gallery.
Schema: /api/v1/themes/schema (authenticated).