- Defer continuation offers for background completions that land while a
  root turn is active and un-finalized; finalize offers exactly one wake
  only when unhandled completed work remains
- Stop late monitor-event mutations from erasing in-turn handled marks, so
  injected-turn ack chatter is never retained as wake evidence
- Clear stale wake buffer frames at non-continuation user-turn start
- Make the late-mutation suppress logic's running/terminal branches
  mutually exclusive