Add privacy settings allowing users to control visibility of their followers, following, posts, and favorites lists with three visibility levels: everyone, following, and self. Also implement account deletion workflow with 30-day cooldown period.
- Add PrivacySettings model with visibility levels
- Add DTOs for privacy settings and account deletion
- Add repository methods for privacy settings and deletion
- Add service methods to check visibility permissions
- Add handlers for get/update privacy settings and account deletion
- Add new routes for privacy settings and account management
- Add account cleanup service for hard-deleting expired accounts
- Modify login to cancel deletion when user logs in
BREAKING CHANGE: Users with pending_deletion status can no longer log in; logging in now automatically cancels deletion requests.