Two audit P2 quality defects, fixed at engine level.
P2-2 - on-solid text illegible on light solids:
The `contrast` slot defaulted to `--color-content-on-solid` (white) for every
role. On light solids (amber/yellow, risk=orange ~2.3:1) white is sub-AA. The
engine now picks by WCAG contrast (gamma-linearized) of the role step-9: when
white fails (<3:1) it uses `--color-content-on-solid-contrast` (a dark, new
OPTIONAL `content.onSolidContrast` semantic, #1c1917 in base). Only risk flips
to dark in base (5.89:1); purple/red/teal/green keep white (convention, >=3:1).
An explicit `slots.contrast` override is still honored verbatim.
P2-4 - opaque tinted soft surfaces:
The soft variant tint (Button + Badge `{role}-soft-bg`) was opaque (step-1 track
+ opaque color-mix hover) so it did not composite over non-uniform backgrounds.
New derived tokens `--color-{role}-surface` (= a2) + `--color-{role}-surface-hover`
(= a3) are translucent by construction (compositing-inverse alpha). Button/Badge
soft consume them. Toast/Tabs untouched - they are cards, opacity is correct.
- config-types: optional onSolidContrast + CONTENT_COLOR_OPTIONAL_KEYS.
- config: content keySet allows the optional key; validator value-checks it.
- render-css: wcagContrastRatio/wcagRelativeLuminance; luminance pick; emit
on-solid-contrast + surface/surface-hover.
- contract: on-solid-contrast + surface tokens per role.
- themes/base: onSolidContrast #1c1917 (light + dark).
- recipes/base: Button + Badge soft-bg -> surface, soft-bg-hover -> surface-hover.
- docs: THEMING.md section 24 + section 22 item 2; audit P2-2/P2-4 resolved.
Verified: npm run check (0 new errors), vitest eidos (0 new regressions),
browser runtime (risk 5.89:1 dark text, surfaces translucent rgba).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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