Добавил домен

backend/UniVerse.Domain/Exceptions/ForbiddenException.cs

@@ -0,0 +1,9 @@
+namespace UniVerse.Domain.Exceptions;
+
+public class ForbiddenException : Exception
+{
+    public ForbiddenException(string message = "You do not have permission to perform this action.")
+        : base(message)
+    {
+    }
+}