pub async fn check_git_available() -> boolExpand description
Check if git is available on the system.
This is memoized so repeated calls within a session return the cached result. Git availability is unlikely to change during a single CLI session.
Only checks PATH – does not exec git. On macOS this means the /usr/bin/git
xcrun shim passes even without Xcode CLT installed; callers that hit
xcrun: error: at exec time should call mark_git_unavailable() so the rest
of the session behaves as though git is absent.