iter_plugin_dirs stat'd <child>/__init__.py inside every plugin dir, so a single mode-000 / ACL-denied $HERMES_HOME/plugins/<x> still raised PermissionError out of the loader, memory-provider discovery (dashboard memory settings, hermes memory setup, plugins memory picker) and the user cron-provider scan. Catch OSError per child and log the same 'Skipping unreadable plugin directory' warning the list path already emits. Part of #111804