fix(ui): selection is an opaque pair, primary-foreground on primary - #2573

🟢 Confidence 10/10 · safe to merge. Opaque pair computes to 6.5:1 (light) and 7.9:1 (dark), and the chip rule reaches the kit path that renders every badge.
_{no findings · tests not needed · risk medium}

Makes ::selection an opaque primary-foreground on primary pair and exempts chips (badges, text-on-fill, text-primary-foreground) from the band, plus matching design-rules text. Contained CSS change, safe to merge.

• ::selection pairs primary-foreground on primary instead of a 40% wash
• Chips drop the band for a 1px currentColor underline
• native-select.styles.ts loses its own redundant selection: pair

_{9d51585 · Reply "won't fix" to dismiss a finding, or mention @maple-review-bot to ask about one.}