Fixed namespace error.

LibraryApp.Domain/Services/Result.cs

@@ -0,0 +1,14 @@
+using LibraryApp.Domain;
+
+namespace LibraryApp.Services;
+
+public record Result
+{
+    public required bool IsSuccess { get; init; }
+    public Error? ErrorMessage { get; init; }
+
+    private Result() { }
+
+    public static Result Success() => new Result { IsSuccess = true };
+    public static Result Failure(string errorMessage) => new Result { IsSuccess = false, ErrorMessage = errorMessage };
+}