When the converter derives a site's Box Presets, do we replace the built-in defaults or keep them?
The question: After the Site Converter walks a source and clusters every box skin into on-brand Box Presets, what happens to the plugin's four built-in defaults (Card / Outline / Soft Shadow / Hover Lift)? Do the site-derived presets replace them, or do both coexist — and if both, in what order?
