Codex review of PR-A found three blockers:
- A throwing step/start session-event listener left an unbalanced log
(turn/start → step/start → turn/end with no step/end), which the invariants
oracle rejects — masked because that rejection was itself contained as a
throwing turn/end listener. Fix the root cause in the loop: mark the step open
BEFORE appending step/start (Session.append pushes before notifying), so the
outer catch's closeStep() appends the balancing step/end. The test now asserts
the balanced outcome (stepEnd:1, step/end before turn/end); proven load-bearing
(revert the reorder → the test goes red with stepEnd:0).
- Reintroduce the /goal-pattern guard deleted in the prior commit, migrated to a
step/end session-event listener (the surviving step-boundary hook point), with
a no-tools first step so it exercises the hasSteering continuation override.
- Update packages/core/agent/README.md: step boundaries are no longer agent/*
emits.
Tianyi Cui
8df89d8e33