Earlier quoted context omitted.
Where is Claude's checkout? Do you have them all share the same local files or does each use its own copy?
People are doing this lots of different ways. Some run it in its own containers or in instances on the web. Some are using git worktrees. I use a worktree for anything large, but smaller stuff is just done in the local files. Sloppy? Perhaps, but Claude has never made such a big mess that it has needed its work wiped.
I think a key thing to point out to people here is that Claude's built in editing tools won't generally allow it to write to a file that has changed since last time it read it, so if it tries to write and gets an error it will tend to re-read the file, adjust its changes accordingly before trying again. I don't know how foolproof those tests are, because Claude can get creative with sed and cat to edit files, and of course if a change crosses file boundaries this might not avoid broken changes entirely. But generally - as you said - it seems good at avoiding big messes.