Two follow-ups from self-review:
1. Add unit test for _fetch_models_from_api covering the live HTTP path.
The salvaged PR #19530 dropped the supported_in_api:false filter in
both _fetch_models_from_api and _read_cache_models, but only the
cache path had a regression test. This adds the symmetric live-fetch
test (mocked httpx) so a future drive-by change to the HTTP path
can't silently re-introduce the filter.
2. Pin test_codex_picker_uses_live_codex_catalog to the cache fallback.
The test wrote a fake JWT and a CODEX_HOME cache, but provider_model_ids
('openai-codex') still issued a real 10s HTTP probe to
chatgpt.com/backend-api/codex/models before falling back to the cache.
That made the test slow and non-deterministic in restricted/CI
networks. Patch _fetch_models_from_api to return [] so we go straight
to the cache path the test actually means to exercise.
826e7171e9