fix: 'NotFound'-Flag zur Flag-Enum hinzufügen, um fehlende Ressourcen oder Operationen anzuzeigen

DigitalData.Core.DTO/Flag.cs

@@ -39,6 +39,12 @@
         /// Indicates that either a possible security breach, a possible data integrity issue, or both have been detected during the service operation.
         /// This flag is used when it is uncertain whether the issue is related to security, data integrity, or both.
         /// </summary>
-        PossibleSecurityBreachOrDataIntegrity
+        PossibleSecurityBreachOrDataIntegrity,
+
+        /// <summary>
+        /// Indicates that the requested resource or operation could not be found.
+        /// This flag is used when the specified item or condition does not exist or is unavailable.
+        /// </summary>
+        NotFound
     }
 }