fix(passport): handle 409 conflict as success in registerOffchain

- Treat 409 Conflict error as success (user already registered)
- Check for multiple error indicators: '409', 'conflict', 'already registered'
- Add informative log message for debugging
- Prevents unnecessary error display to users who are already registered

Author: rodrigo-fournier-immutable

Source/Immutable/Private/Immutable/Actions/ImtblPassportImxRegisterOffchainAsyncAction.cpp

@@ -49,5 +49,15 @@ void UImtblPassportImxRegisterOffchainAsyncAction::OnImxRegisterOffchainResponse
 		}
 	}
 
+	// Handle 409 Conflict error - user already registered
+	// This is a normal case and should be treated as success
+	if (Result.Error.Contains(TEXT("409")) || Result.Error.Contains(TEXT("conflict"), ESearchCase::IgnoreCase) ||
+	    Result.Error.Contains(TEXT("already registered"), ESearchCase::IgnoreCase))
+	{
+		IMTBL_LOG("User is already registered offchain (409 response treated as success)");
+		OnSuccess.Broadcast(TEXT(""), TEXT(""));
+		return;
+	}
+
 	OnFailure.Broadcast(TEXT(""), Result.Error);
 }