Add comprehensive design system documentation:
- Z-index scale (z-10 through z-[100])
- Spacing scale based on 4pt baseline
- Opacity guidelines for glass/translucent effects
- Transition timing standards (150-300ms)
- Focus state requirements
- Cursor affordance rules
- WCAG AA contrast requirements
- Button state implementation patterns
- Form element best practices
- Modal hierarchy guidance
- Migration checklist
Accessibility improvements:
- Add alt text to OCR preview image in Scanner
- Verify all images have descriptive alt text
- Establish transition consistency guidelines
This ensures design consistency and accessibility across the application.
