/**
 * test_queue_scheduler — Story 6.3 regression suite.
 *
 * Four scenarios:
 *   1. enqueue + tick + happy path: missions transition pending→running→
 *      completed; queue file persists each transition atomically.
 *   2. Backpressure: maxConcurrent caps the in-flight set; extras wait.
 *   3. Lock-respect: a mission whose lock is already held by another
 *      DistributedLock instance is NOT picked up.
 *   4. reconcileOrphans: a queue with stale `running` items (no holder)
 *      resets them to `pending` on the next start.
 *
 * Prints TEST_QUEUE_SCHEDULER_OK on full pass.
 */
export {};
