The project you used in 101, under git and at a clean working tree: git status --short prints nothing.
Exercise 1 starts from scratch, with no guidance file in the project. If the project has a CLAUDE.md, from before the course or since, Exercise 1 moves it aside and Exercise 3 reads it against the new one.
A second project you use the same agent on, for Exercise 4. Without one, use the project you worked on most recently before this one.
A shell. The examples use zsh, the shell the course's evidence comes from.
