[TheDemonTuan]

Summary

• add GPT-6 Astra fallback models and raise the tested Codex compatibility version to 0.153.4
• classify remote Codex models before activation so hidden, unsupported, retired, or newer-client models cannot enter the active catalog
• expose optional candidate diagnostics while persisting only active models

Validation

• node --import tsx/esm --test tests/unit/provider-models-discovery-split.test.ts tests/unit/codex-reasoning-suffix.test.ts
• npm run typecheck:core
• npm run lint -- --quiet --pass-on-unpruned-suppressions

⚠️ base-red inherited: #12732

[diegosouzapw]

This is a genuinely valuable safety fix — preventing hidden/unsupported/retired/newer-client
models from silently entering the active catalog is exactly the right instinct, and the
active/candidate split is a clean way to do it without losing the diagnostic signal. I ran your
two test files at the PR head: 36/36 pass. Two things before merge: (1) could you add a
changelog fragment under changelog.d/? I didn't find one in the diff. (2) this overlaps
textually with #13224 and #12893 (same file, same buildCodexDiscoveryModel function) — the
maintainer will need to sequence these three rather than merge them independently. Flagging that
coordination need rather than asking you to guess at a moving target.

[TheDemonTuan]

Added the changelog fragment under changelog.d/features/12933-codex-safely-discover-compatible-models.md (6d297b9).

Understood regarding the sequencing with #13224 and #12893 on �uildCodexDiscoveryModel — happy to rebase or help adapt if needed once you sequence them. Thanks!

[diegosouzapw]

Thanks @TheDemonTuan — merging via the release merge-train. Validated in local merge-train (merge-train-20260918-120911-suite.log) on the devbox @ train tip 8c305709478b7052fb981a75852bbf88fe3a959d with the sibling PRs of this batch: typecheck:core, file-size, complexity, cognitive-complexity, changelog-integrity green; changed-area node:test 310/311 (the single red, hard-lease inventory, reproduces on the pure release tip) + vitest green (fast parity mode — full suite ran today on the tip via the base-red and 3b trains). Merged --admin per merge-gates §4/§7.