In a group take-in that changes the runner, the other members' pipelines are held for the new runner, so the
group never ended before the bound and the new runner was never wanted. The runner is the acting part the
others wait on, so it goes first as the node-engine does: its member (the holder of the seat
mesh-pipeline-runner, read from the acting edges) is wanted on its own pipeline-ended once that passed, ahead of
the group; the other members keep the group's end.
Builds: design 47 G §29, §65, §268; A-328, A-334
Claude-Session: https://claude.ai/code/session_01NcbgfGKaxw984XyAPfLm4h