Recall continuation resource limits

Trap: charging every continuation buffer to maxDeferredBytes looks uniform, but that cap applies only to unresolved, untrusted tool input. Charge validated client-visible output to maxTransactionalBytes; when a sparse non-recall call resolves, transfer its deferred bytes exactly once before flush. Before retry, restore transactional events/bytes, retained and hidden bytes, usage, and output/reference identity sets to baseline so retries cannot duplicate accounting or retain stale identities.