/** Own a JSON-like input at the call boundary; never retain consumer objects. */
export function snapshotOrgChartDataset<T>(input: T): T {
  const copy = structuredClone(input);
  const pending: unknown[] = [copy];
  const seen = new WeakSet<object>();
  while (pending.length) {
    const current = pending.pop();
    if (current === null || typeof current !== 'object' || seen.has(current)) continue;
    seen.add(current);
    for (const child of Object.values(current)) pending.push(child);
    Object.freeze(current);
  }
  return copy;
}