Update default Audience value in AuthTokenKeys

Changed the default Audience property in AuthTokenKeys from "sign-flow-gen.digitaldata.works" to "sign-flow.digitaldata.works" to reflect the correct expected audience for authentication tokens.

EnvelopeGenerator.API/Models/AuthTokenKeys.cs

@@ -24,5 +24,5 @@ public class AuthTokenKeys
     /// <summary>
     /// Gets the expected audience value for the authentication token.
     /// </summary>
-    public string Audience { get; init; } = "sign-flow-gen.digitaldata.works";
+    public string Audience { get; init; } = "sign-flow.digitaldata.works";
 }