Extract hardcoded colors from 15+ component files into a centralized
token system (tokens.ts + shared-styles.ts) so all UI colors flow
through FoundryTokens. This eliminates 160+ scattered color values
and makes light mode a single-file change in the future.
- Add FoundryTokens interface with dark/light variants
- Add shared style helpers (buttons, cards, inputs, badges)
- Bridge CSS custom properties for styles.css theme support
- Add useFoundryTokens() hook and ColorMode context
- Migrate all mock-layout/* and mock-onboarding components
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>