- Add duplex + style_href to properties_to_save so they're cached in IDB
- Derive show_badge_back: true when duplex is null/unset (safe default for
existing templates) or 1; false when duplex=0 (single-sided, e.g. Axonius
NYC using Zebra ZC10L PVC cards)
- Wrap entire badge_back section in {#if show_badge_back} so the DOM node
is fully removed rather than just hidden — cleaner than a CSS class approach
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>