Добавил домен

backend/UniVerse.Domain/Entities/RefreshToken.cs

@@ -0,0 +1,18 @@
+namespace UniVerse.Domain.Entities;
+
+public class RefreshToken
+{
+    public int Id { get; set; }
+    public int UserId { get; set; }
+    public string Token { get; set; } = string.Empty;
+    public DateTime ExpiresAt { get; set; }
+    public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+    public DateTime? RevokedAt { get; set; }
+
+    public bool IsExpired => DateTime.UtcNow >= ExpiresAt;
+    public bool IsRevoked => RevokedAt != null;
+    public bool IsActive => !IsRevoked && !IsExpired;
+
+    // Navigation properties
+    public User User { get; set; } = null!;
+}