Codex review of the turn-mirror removal found current-state docs/comments that
still claimed the removed `agent/turn-start`/`agent/turn-end` events exist:
- docs/architecture.md: the loop diagram's turn-start line still said "emit
agent/turn-start" (the turn-end line was already fixed).
- event-domain-semantics RFC: the `agent/*` domain description listed "the turn
boundaries" among the transient emits.
- docs/core-data-structures/core.md: the agent/* taxonomy blurb listed
"turn/step boundaries" as agent events.
- the proposed ACP RFC: the settle-signal rows named agent/turn-start /
agent/turn-end; retargeted to the durable `turn/end` session event + the
session/event owning-turn correlation.
- loop.ts outer-catch comment: said "closeTurn/failTurn are idempotent" — after
the emit-param removal closeTurn is called exactly once (mutually exclusive
normal/catch paths), so corrected to state that and to scope idempotency to
closeStep (which is still guarded by stepOpen).
Regenerated the cordis catalog. No behavior change.