WCAG 2.1 AA accessibility audit + fixes for Stellar flows

[truthixify]

Tier: L (1-2 weeks) Type: a11y

Context

audit

Scope

No formal a11y review has happened. Dark monochrome + tight typography + crypto UX patterns are an accessibility risk. Need structured WCAG 2.1 AA audit + fix Critical/Serious in same PR.

Acceptance criteria

• Tools: axe-core, Lighthouse a11y, WAVE, manual keyboard nav, VoiceOver / NVDA sweep
• Per-page findings table in docs/A11Y.md (severity, WCAG criterion, element, fix)
• Fix Critical + Serious in this PR
• Specific things: color contrast on text-outline against surface, focus indicators on every interactive element, keyboard nav (skip-link, focus trap in modals), screen-reader labels on icon-only buttons (copy button), reduced-motion respect, semantic structure (single h1, landmark regions)
• vitest-axe smoke tests in CI

Files to start with

• docs/A11Y.md committed with findings table
• All Critical + Serious findings fixed
• vitest-axe CI gate
• VoiceOver run-through documented
• axe reports zero violations on home page

Why this matters

• All src/components/*.tsx
• src/index.css (color tokens)