Preserve explicit model and provider architecture (#30)

frontend/packages/sxchnge_auth/lib/src/mappers/results.dart

@@ -0,0 +1,13 @@
+import '../dto/results.dart';
+import '../models/auth.dart';
+import '../models/verification.dart';
+
+abstract final class AuthMapper {
+  static AuthResult fromDTO(AuthDTO dto) =>
+      AuthResult(userId: dto.userId, isSimulated: dto.simulated);
+}
+
+abstract final class VerificationMapper {
+  static VerificationResult fromDTO(VerificationDTO dto) =>
+      VerificationResult(isSimulated: dto.simulated);
+}