sourceAge keyed AgainTo's clause-6 refusal on the stream's bus retention
policy, which SEAT_* and other mesh-internal work queues share without
being one of ADR 0436 §6's module streams — so every seat's ask, once
given up on, was refused delivery again. Added a dedicated metadata key
(WorkQueueMetadata), set only by ModuleStream.Stream() when the
catalogue declared retention: work-queue, and read sourceAge from that
instead of the stream's retention policy. New test proves a seat's own
work queue carries neither that metadata nor the restricted one.
jochen
1991fe931b