make checkboxes match figma/design system version

Signed-off-by: eti eti@eti.tf
make checkboxes match figma/design system version

Signed-off-by: eti eti@eti.tf
Native accent-color approach didn't match the Figma design system.
Custom appearance-none implementation covers all six states: default,
hover, checked, disabled, disabled-checked, and indeterminate.
Uses Lucide check/minus paths as readable SVG data URIs.
Signed-off-by: eti <eti@eti.tf>