- Remove 'user created successfully' alert after user creation
- Replace edit user placeholder alert with fully functional edit modal
- Add update_user() method to AuthManager with validation
- Add update_user() method to DashboardAPI class
- Add PUT /api/users/{user_id} route for user updates
- Edit modal includes form validation and error handling
- Pre-populates current user data in edit form
- Supports updating username, email, password (optional), and admin status
- Validates username/email uniqueness before saving
- Automatically refreshes user list after successful updates

User management interface is now fully functional with create, edit, and delete operations.