Pre-commit a11y axe-mcp, check accessibility avant commit
Pre-commit a11y gate pattern: integrate axe-mcp (or open-source a11y-mcp) in the pre-commit hook (husky + lint-staged) to scan staged files and reject commit if critical violations detected. Combined with axe-core in CI (authoritative blocking), this is the a11y double-loop: fast dev feedback + non-bypassable gate.