Preserve explicit model and provider architecture (#30)

frontend/packages/sxchnge_wallet/lib/src/services/dummy.dart

@@ -204,7 +204,7 @@ class DummyWalletService implements WalletService {
   @override
   Future<AccountProfile> profile() async {
     await _wait();
-    return WalletMapper.profile(_locale);
+    return WalletMapper.profile(ProfileDTO(_locale));
   }
 
   @override
@@ -213,7 +213,7 @@ class DummyWalletService implements WalletService {
     if (!['en', 'ru'].contains(locale))
       throw const WalletException(WalletError.unsupported);
     _locale = locale;
-    return WalletMapper.profile(_locale);
+    return WalletMapper.profile(ProfileDTO(_locale));
   }
 
   // Kept separate from wallet fetch because LimitsService has a different result.