Function resolve_config_dir_for_data 

pub fn resolve_config_dir_for_data(data_dir: &Path) -> (PathBuf, PathBuf)

Resolve the install a ZEROCLAW_DATA_DIR (or deprecated ZEROCLAW_WORKSPACE) value points at: its config directory and that install’s data directory.

The value locates the install. It is the install itself when it holds a config.toml, or the data directory beside a .zeroclaw install (as in the container images). The data directory returned is always the install’s own <config-dir>/data, which is where Config::load_or_init keeps the databases.