## Why
We need request-level evidence for Guardian cases where
`codex-auto-review` is missing from the client-side model catalog and
the review falls back to the parent model.
## What changed
- Add `guardian_catalog_contains_auto_review` to Guardian Responses API
client metadata.
- Add `guardian_model_provider_id` to Guardian Responses API client
metadata.
- Keep review-session metadata optional so callers without metadata
preserve the existing `None` path.
- Add tests for override, normal preferred-model, and
missing-auto-review-catalog behavior.
## Validation
- `just test -p codex-core
guardian_review_records_missing_auto_review_model_in_request_metadata`
- `just test -p codex-core
guardian_review_uses_model_catalog_override_when_preferred_review_model_exists`
- `just test -p codex-core
guardian_review_uses_preferred_review_model_without_model_catalog_override`
- `git diff --check origin/main`