Smart Export Panel Redesign
Redesigned the asset export panel from a single scrolling form into a two-view flow: browse presets, then configure and preview.
- List → detail navigation — first screen shows all available presets as cards. Pick one and the panel slides to the detail view with live preview, crop strategy selector, and export button. Back arrow returns to the list.
- Live crop preview — switching crop strategies or presets regenerates the preview via the smart crop API with a 400ms debounce and AbortController cancellation. A spinner overlays the existing preview while the new one loads.
- Attention crop fix — crop offsets were being scaled by coverScale, displacing the crop window from where Sharp's attention detection actually focused. Fixed by using Sharp's native attention strategy directly.
- Alpha flattening — centerCrop now flattens transparent pixels when the background is opaque, preventing alpha artifacts from leaking into marketplace exports.
- Pre-resize for speed — source images larger than 1200px are downsized before preview generation for faster response.