prevent dup wallets

Toolkit.Foundation/Error.cs

@@ -0,0 +1,14 @@
+namespace Toolkit.Foundation;
+
+public record Error(string Code, string Message)
+{
+    public static readonly Error None = new(string.Empty, string.Empty);
+
+    public static readonly Error Null = new("Error.NullValue", "The specified result value is null.");
+
+    public static readonly Error ConditionNotMet = new("Error.ConditionNotMet", "The specified condition was not met.");
+
+    public static readonly Error Duplicated = new("Error.Duplicated", "The specified item already exists.");
+
+    public static readonly Error Failure = new("Error.Failure", "The operation has failed.");
+}