feat(apps): establish shared mobile design system

apps/service_app/pubspec.yaml

@@ -30,6 +30,8 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
+  heqi_design_system:
+    path: ../heqi_design_system
 
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.