phsl / new-api

- Replace lucide-react icons with Semi UI icons for consistency
- Implement Steps component for guided 2FA setup modal flow
- Redesign disable and regenerate backup codes modals to match setup modal style
- Extract duplicate backup codes display logic into reusable BackupCodesDisplay component
- Move modal navigation buttons to proper footer parameter following Semi UI standards
- Replace custom styled dots with Badge components (warning/danger/success types)
- Use Banner and Divider components for better visual hierarchy
- Remove redundant modal step titles and download functionality
- Apply consistent rounded corners, spacing, and color scheme across all modals
- Improve responsive design with maxWidth constraints

This unifies the 2FA settings visual design with other settings pages and
enhances user experience through better component usage and layout structure.