/**
 * test_distributed_lock — Story 6.4 regression suite.
 *
 * Four scenarios:
 *   1. Acquire + release happy path; peek round-trips the record
 *   2. Collision — second acquire on same key fails while first holds
 *   3. TTL expiry — stale lock can be taken over after ttlMs elapses
 *      (test uses a tiny ttlMs and a controlled busy-wait, no sleep)
 *   4. Renew + steal-detection — renewing a lock we no longer own
 *      (file overwritten by an attacker simulation) returns false
 *
 * Prints TEST_DISTRIBUTED_LOCK_OK on full pass.
 */
export {};
