Function legacy_plugin_dirs_with_entries 

pub fn legacy_plugin_dirs_with_entries(config: &Config) -> Vec<PathBuf>

Returns the legacy plugin directories that still hold installed plugins not visible to the runtime, which now scans PluginsConfig::resolved_plugins_dir.

Historically zeroclaw plugin install wrote to <data_dir>/plugins (and, before the data-dir rename, <install_root>/workspace/plugins). A directory is reported only when it differs from the configured plugins dir and contains at least one plugin (a subdirectory with a manifest.toml). Used to surface a migration hint and to drive zeroclaw plugin migrate.