Add values module to the css crate that converts raw ComponentValue token lists into typed CssValue variants. Supports all CSS length units (px, pt, cm, mm, in, pc, em, rem, vw, vh, vmin, vmax), percentages, hex colors (#rgb, #rrggbb, #rgba, #rrggbbaa), rgb()/rgba() functions, 17 named colors, keywords (auto, inherit, initial, unset, none, transparent, currentColor), and shorthand expansion for margin, padding, border, border-width/style/color, and background. 63 unit tests covering all value types and shorthands. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>