Function check_app_data_dir 

pub fn check_app_data_dir(
    guard: &Guard,
    app_binary: &Path,
    env: &[(String, String)],
) -> Result<(), UserDataViolation>

App launches get their data directory from the workspace: the launch environment must carry RIGHTKIT_QA_DATA_DIR, pointing inside the QA root guard was built for. A workspace whose environment lost it is refused rather than launched on the app’s own default folder.