Move sdk stubs to the spike, that uses it.

.gemini/GEMINI.md

@@ -40,3 +40,10 @@ When the CatalogItem API changes, it is necessary to update all the existing cat
 ## How to update every CatalogItem
 
 1. Find all CatalogItem implementations which will be at `examples/travel_app/lib/src/catalog/*`, `pkgs/flutter_genui/lib/src/catalog/*` etc. Update each of them.
+
+## Folder `spikes`
+
+The folder `spikes` contains experiments and proof of concepts,
+that does not have to be of good quality.
+
+Skip this folder when reviewing code.

pkgs/flutter_genui/lib/flutter_genui.dart

@@ -14,7 +14,3 @@ export 'src/model/catalog.dart';
 export 'src/model/catalog_item.dart';
 export 'src/model/dynamic_ui.dart';
 export 'src/model/ui_models.dart';
-export 'src/to_merge/agent/agent.dart';
-export 'src/to_merge/model/controller.dart';
-export 'src/to_merge/model/image_catalog.dart';
-export 'src/to_merge/model/input.dart';

pkgs/spikes/travel_app_hardcoded/lib/app.dart

@@ -1,5 +1,9 @@
 import 'package:flutter/material.dart';
-import 'package:flutter_genui/flutter_genui.dart';
+
+import 'sdk_stubs/agent/agent.dart';
+import 'sdk_stubs/model/controller.dart';
+import 'sdk_stubs/model/image_catalog.dart';
+import 'sdk_stubs/model/input.dart';
 
 class MyApp extends StatelessWidget {
   const MyApp({super.key});

pkgs/spikes/travel_app_hardcoded/pubspec.yaml

@@ -11,6 +11,7 @@ dependencies:
     sdk: flutter
   flutter_genui:
     path: ../../flutter_genui
+  url_launcher: ^6.2.6
 
 dev_dependencies:
   dart_flutter_team_lints: ^3.5.2