public class ClinicalUser { public Guid Id { get; set; } public string Username { get; set; } = null!; public string PasswordHash { get; set; } = null!; public string DisplayName { get; set; } = null!; public ClinicalRole Role { get; set; } public bool IsActive { get; set; } = true; public DateTimeOffset CreatedAt { get; set; } public DateTimeOffset? LastLoginAt { get; set; } }