I followed the Quick Tutorial and everything works somehow. I removed all these models and views but even after a ./gradlew clean, they are still available in the application.
How can I completely remove these views/models? I run the application in dev mode using Idea run which should be the same as ./gradlew run
These objects are stored in the database.
In addition to the actions you are already doing, try deleting these objects in the database, via the menu Administration > View Management > All Views / All Actions
For models, Administration > Models Management > All Models. In the latter case, if you delete models, ensure consistency with your database, because the corresponding tables will not be deleted.