pub fn homebrew_var_dir_from_exe(exe: &Path) -> Option<PathBuf>Expand description
Detect if the executable lives under a Homebrew prefix and return the
corresponding var/zeroclaw directory.
Homebrew installs binaries into <prefix>/Cellar/<formula>/<version>/bin/
and symlinks them through <prefix>/bin/ and <prefix>/opt/<formula>/.
The canonical var directory is <prefix>/var.