At every start an ordered consumer, made for the one read, hands every message from the first, then the
durable is followed, so a part that keeps what an age-kept seat event said (the assigner's version-released
and version-delivered) knows it again after a restart.
Builds: design 47 G A-233, A-189, A-181
Claude-Session: https://claude.ai/code/session_01NcbgfGKaxw984XyAPfLm4h