Constant NEVER_SCANNED_KEYS 

const NEVER_SCANNED_KEYS: &[&str];

Keys whose values the value scan must leave alone: they carry ids shaped like student numbers — cr-{uuid} request item ids, Sisu ids such as hy-CUR-135176012 — that the scan would mangle.

Container keys do not belong here: an exemption stops at the objects below it.