Two small a11y fixes for the floating legend.
1. Both buttons (open pill + close ×) had no focus-visible ring —
keyboard users couldn't tell where focus landed. Added the
accent-ring pattern used across the rest of the canvas.
2. Close button was a ~10x16px hit area — well below WCAG 2.5.5's
24x24 minimum. Bumped to w-6 h-6 with negative margin so the
visible × stays in the same spot but the hit area + focus ring
are larger. Hover bg added to make the hit area visible on hover.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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