Farvist v0.7.0 — accessibility

Accessibility pass. farvist.js now auto-applies ARIA: form aria-invalid/describedby, toast live regions (danger=assertive), tooltip descriptions exposed to screen readers, aria-current on breadcrumb/stepper/pagination, progressbar names, and keyboard-scrollable tables/code blocks. Adds a .skip-link utility, a theme-aware --fv-primary-text token that fixes WCAG AA contrast for links and outline/link buttons on dark, :focus-visible polish, and a docs Accessibility section. Verified: 0 axe-core (WCAG 2 A/AA) violations across all 8 pages in both themes. Also fixes the JS global (window.Farvist + Farvistrap alias). Live: https://farvist.com