A review ends a placed review step with its proven caller; rerun asks a step again under a new ask saying it is a rerun
and by whom; accept takes a failed optional step; cancel ends a running pipeline cancelled and drops its asks' bounds.
Each writes `pipelines` by compare-and-set, says step-ended, step-started or pipeline-ended, and records its hand act
first, through AnswerSeat.
Builds: design 47 G §22, §70, §482, §30, §325, §394, A-107
Claude-Session: https://claude.ai/code/session_01NcbgfGKaxw984XyAPfLm4h
jschoubben
88699377d2