Add turn_id to codex exec JSONL turn.started / turn.completed events

What variant of Codex are you using?

CLI

What feature would you like to see?

In codex exec JSONL output, turn.started and turn.completed currently don’t include a stable turn
identifier.
This forces consumers to pair lifecycle events via mutable positional state, which can break with
cross-batch ordering/replay.

Request:

• Add turn_id to turn.started and turn.completed payloads (additive/backward-compatible).
• Ensure turn.failed correlation is explicit as well (either same turn_id field or documented

equivalent).

• Document the lifecycle pairing contract for exec JSONL.

Why this matters:

• Reliable turn-level observability
• Safer ingestion/ETL pipelines
• Consistent correlation with app-server v2 turn semantics

Additional information

_No response_