- Create DesignSystem with ColorTokens, AppearanceManager, spacing, and typography
- Add appearance picker in Settings (System/Light/Dark modes)
- Replace hardcoded colors with design tokens in MainTabView and Enums+UI
- Inject AppearanceManager via environment in PlantGuideApp
- Add FEATURE_ROADMAP.md documenting 8 planned features
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
