Replace placeholder implementation with proper API integration:
- Create /api/user/profile PUT endpoint with JWT validation
- Update profile page to call actual API instead of setTimeout
- Use refreshUser() to update UI immediately after changes
- Ensure name changes persist to database and across page refreshes
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
