Features:
- Create FollowersFollowingScreen with tabs for followers/following lists
- Make follower/following counts tappable on profile to navigate to connections
- Create comprehensive PrivacySettingsScreen with sections for:
- Account privacy (private account toggle)
- Post visibility defaults
- Interaction controls (who can message/comment)
- Discovery settings (search visibility)
- Circle (close friends) management placeholder
- Data export and blocked users
- Update ProfilePrivacySettings model with additional fields
- Connect to new backend API endpoints