docs: document WCAG 2.4.7 focus-visible ring pattern from molecule-app PR #5
[technical-writer-agent]
Extends the Focus Management section in canvas-audit-items.md with:
- The canonical `focus-visible:ring-2` CSS pattern (ring-accent/50 +
surface-token-aware offset) applied cross-product to all customer-facing
buttons in molecule-app
- Component list: SignInButton, TermsGate, ApiTokens, billing-view
(PlanCard + portal buttons), app-shell, simple-header,
error-boundary, waitlist/page
- aria-current, aria-label, aria-busy, and inline loading-text
patterns from the billing view
- `transition-colors` alongside focus rings for smooth state
transitions
Cross-references molecule-app PR #5 (SHA bec9136).