Normalize app architecture

lib/models/activity/activity.dart

lib/models/settings/settings_global.dart

lib/ui/helpers/app_titles.dart

lib/ui/nav/bottom_nav_bar.dart

lib/ui/nav/global_app_bar.dart

lib/ui/pages/home.dart

lib/ui/pages/playlist.dart

lib/ui/screens/about.dart

lib/ui/screens/activity.dart

lib/ui/screens/main_screen.dart

lib/ui/screens/settings.dart

lib/ui/screens/skeleton_screen.dart

lib/ui/settings/settings_form.dart

lib/ui/settings/theme_card.dart

lib/ui/skeleton.dart

lib/ui/widgets/app_bar.dart

lib/ui/widgets/error.dart

lib/ui/widgets/main_screen/user_card.dart

pubspec.lock

pubspec.yaml