Theme Atelier & Preset Adapter Protocol

Iframe isolation, strict origin-validated postMessage synchronization, and preset capability declarations.

The Theme Atelier renders each theme inside a dedicated, lazy-loaded <iframe> at /preview/[theme]/[page] (or an explicitly allowlisted local origin). Preview styles and scripts never leak into the outer storefront.

Each theme manifest declares its supported color schemes, typography pairings, accent tokens, and layout density presets. When a visitor selects an option that a theme intentionally omits (such as dark mode on White Boutique), the workbench surfaces a transparent capability notice rather than inventing broken styles.