When on Windows, the models default to bash / coreutils conventions until they realize it doesn't work / not available unless explicitly instructed otherwise.
Even on Mac, they tend to default to bash instead of running things in zsh.
nope. With ClaudeCode you can create skills ( basically markdown instructions) to teach your agents what command to use. You can also update CLAUDE.md to inject custom instructions that are feeded anything ClaudeCode is started.