Did you build the custom components? The default setting of the cookiecutter does not have any JS. It seems that you have chosen the one with custom widgets which aim to show how you can integrate your own JS code into trame. And if you look at the README of the generated project, it should mention that you have to build the web part first.
To summarize, the cookie cutter should work out of the box. But depending on which template you base your project on, you may need to build your custom client library before your local application can be installable/usable.
Also before trying the docker, you need to make sure it works first.
So far it was not clear if the problem was within the docker/launcher or just the app itself.