Extracts hasMemberAccess(member) in tickets.js and uses it across event registration, ticket purchase, and series purchase flows so guest, suspended, and cancelled records no longer count as members while pending_payment still does.
Add comprehensive testing covering 420 unit/handler tests across 24 Vitest files, 9 Playwright E2E specs, accessibility scans, and visual regression. Includes GitHub Actions CI, Husky pre-push hook, and TESTING.md docs.
