At the moment, the structure of Cumulocity web applications built with the web SDK differs from typical Angular applications. For example you are missing the angular.json file. This is also the case for the Cumulocity Application Builder. Because of the different structure, you can’t run any Angular CLI commands within the project as the project isn’t recognized as an Angular project.
What’s the reason you want to run Angular commands within the Application Builder project? What kind of commands do you want run?