Leonie #5507 concern 3: hover and aria-selected both used bg-canvas, so
a tablet user sweeping the trackpad couldn't tell where the keyboard
cursor was. Use bg-brand-mint/20 + a 2px ring-inset for the highlighted
row — keeps hover affordance, adds a distinct keyboard-cursor token
that meets WCAG 1.4.11 Non-Text Contrast.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>