The crop canvas was sized to cropArea.width/height, which are the editor's
on-screen (CSS) pixels — a few hundred px. Phone photos were therefore
downscaled to that size before upload, so cropped product images came out
blurry (most visibly on iPhone, whose source photos are large).
Size the canvas to the crop region in the source image's native pixels
(adjustedCropWidth/Height, already computed) and draw 1:1. Bumped JPEG
quality 0.9 -> 0.92. The backend still caps the final image to 1600px webp,
so output size stays bounded.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>