Show accepted signup delivery without a second send step (#62)

frontend/packages/sxchnge_auth/lib/src/models/auth.dart

@@ -1,4 +1,5 @@
 import 'two_factor.dart';
+import 'verification.dart';
 
 /// Ephemeral input: never persist, log, or include passwords in provider state.
 class LoginRequest {
@@ -31,9 +32,11 @@ class AuthResult {
     required this.userId,
     required this.isSimulated,
     this.challenge,
+    this.delivery,
   });
   final String userId;
   final FactorChallenge? challenge;
+  final VerificationDelivery? delivery;
   final bool isSimulated;
 }