[codex] Instrument rollout persistence bytes

[wiltzius-openai]

• Add 1%-sampled rollout persistence metrics that report per-item and per-thread JSON byte totals before and after filtering when metrics export is enabled.
• Tag each item with its exact response or event variant, including nested turn-item kinds for conditionally persisted completion events, so aggregate cloud-storage impact can be estimated by policy choice.

[chatgpt-codex-connector]

💡 Codex Review

codex/codex-rs/thread-store/src/live_thread.rs

Line 92 in 9a088ae

params: CreateThreadParams,

Include session metadata in byte totals

For newly created local threads that eventually materialize a rollout, the recorder writes the initial SessionMeta row before pending items, but telemetry starts with empty totals here and the only measurements are taken from later append_items calls. That means the persisted session metadata—often including base instructions and dynamic tool definitions—is never included in the per-thread post_filter byte totals, so successful new-thread shutdown metrics systematically undercount storage impact. Seed the telemetry with the created metadata or record it where the recorder writes it.

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".