which() looked for the bare name only, so on Windows every tool (claude.exe,
codex.cmd, ...) read installed: false. It now tries each PATHEXT extension
(default .EXE;.CMD;.BAT), the bare name only when it already carries one -
npm's extensionless shim beside codex.cmd is a sh script Windows cannot run.
spawnTarget() gives a .cmd/.bat shell: true and a quoted path, used by the
install/update job runner and the npm/version probes, which Node otherwise
refuses with EINVAL (CVE-2024-27980). Catalog argv only.