action #90989

Updated by cdywan 8 months ago

## Motivation
Currently, the workdir is created in the `containers/webui` on containers/webui directory with two problems:

- This clutters populates the git directory. (The path is already in `.gitignore`, though.)
- The directory is owned by root causing the tidy script to fail on permission errors.

## Acceptance criteria

* **AC1**: Use a different default directory or at least prevent the interference with the tidy script.
* **AC2**: Allow to configure the workdir path, e.g. via an environment variable.
* **AC3**: Document where files are stored by default and AC2.