pub fn default_module_cache_dir() -> Result<PathBuf>Expand description
Default cache directory for module git sources.
Honors the thread-local test-home override (set via with_test_home_guard)
so tests can redirect module cache writes off the real ~/.cache/cfgd/.
Without an override this falls through to directories::BaseDirs (XDG on
Linux, ~/Library/Caches on macOS, AppData\Local on Windows).