Work only in a new practice folder. Touch nothing outside it, use no real accounts or keys, and install nothing.
Build a small gate that lets through only a short list of harmless commands, and only inside a work folder. Next to it, make
a secrets file, a file outside the folder, and a shortcut inside the folder that points to that file.
Then build a test that tries about seven ways out (parent-folder path, shortcut, full path, secrets file, deleting, running a
programming language, reading the environment) and prints "refused" or "ESCAPED" per attempt.
I check it by running the test twice: without the gate everything must get through, with the gate nothing.
