TicketHolder and its subclasses use a mix of int and int64_t: int for outof, used, available, peakUsed, maxQueueDepth, and semaphore APIs; int64_t for numFinishedProcessing and QueueStats counters.

Review all such fields and choose fixed-width types (int32_t, int64_t, size_t) based on range, portability, and consistency. Document the rationale for each choice and apply the changes across TicketHolder, TicketSemaphore, and implementations such as UnorderedTicketSemaphore (and others).