Remove repeated demo notes from product screens (#28)

frontend/app/test/verification_test.dart

@@ -57,7 +57,7 @@ void main() {
           find.byKey(ValueKey('verification-${scenario.value}')),
           findsOneWidget,
         );
-        expect(find.textContaining('DEMO'), findsOneWidget);
+        expect(find.textContaining('DEMO'), findsNothing);
         expect(tester.takeException(), isNull);
       },
     );