Farvist v0.11.0 — docs + website polish

Docs + site polish. Copy-to-clipboard on every code snippet (pre.snippet auto-gets a button; Farvist.copy() exposed). Docs scrollspy highlights the section you're reading. Every one of the 34 components now has a dedicated docs section with a live example (new Feedback/Navigation/Data display/Indicators/Inputs/Icons groups). Homepage gains a 'Get started' install block and an honest Farvist-vs-Bootstrap-vs-Tailwind comparison table. Fixed: og:image referenced an og-image.png that never existed — generated the real 1200x630 PNG so social previews render. 0 axe violations, 0 overflow (desktop + mobile). Live: https://farvist.com