Web a11y: key page axe smoke checks

[0xMegie]

Area: apps/web/src/features/**

Goal: Catch baseline accessibility violations on core views.

Tasks:

• Add vitest-axe (or equivalent) checks for faucet, trade, and referrals page renders.
• Assert no critical/serious violations on disconnected states.
• Document how to triage and waive known issues.

Acceptance:

• Checks run in jsdom without real network (MSW stays enabled).
• bun run --cwd apps/web test passes.

[pablowizzy24]

Runs automated accessibility (Axe) checks on key pages to catch common accessibility issues early and ensure a more inclusive user experience.