Phase 1 accepted and phase 2 answered well. One real defect: the supersede path in
runOpenCodeTurn kills a stale turn without marking it, so the dead process late-fires
finish() against the turn that replaced it — committing a false "OpenCode exited" to
chat_session_events, deleting the live handle from `running`, killing the stop button
and orphaning the process.
Predates this pass; reported now because e8bd946 is what made the map load-bearing.
Reproduced with a stub binary rather than argued — the transcript is in the doc.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>