fix: codex model discovery sends prime-agent version as client_version

[ayushnangia]

Fixes #702.

Problem

openAICodexModelsUrl() (packages/coding-agent/src/core/model-registry.ts:386) passed prime-agent's own package VERSION as the client_version query parameter. The ChatGPT backend gates the Codex model catalog by Codex CLI version, so 0.7.0 reads as an ancient client and returns {"models": []}. The empty catalog filters every openai-codex model out of getAvailable(), findRlmModels, and subagent spawns, producing the misleading "unavailable, unauthenticated, or expired" error with fresh auth — exactly as diagnosed in the report.

Change

Pin a verified Codex CLI version (OPENAI_CODEX_CLIENT_VERSION = "0.146.1", confirmed by the reporter to restore the full 9-model catalog with the same bearer token) instead of our own version, with a comment explaining why the package version must not be used. VERSION import dropped from model-registry (now unused there).

Complementary to #717, which fail-opens when discovery legitimately returns empty; this PR makes discovery return the real catalog in the first place. The report's optional suggestion (distinct error for discovery-empty vs auth failure) is left out to keep the change minimal.

Tests

test/suite/regressions/702-codex-client-version.test.ts: stubs fetch, drives findRlmModels through the harness, and asserts the /codex/models request's client_version is not the package VERSION and matches a Codex CLI version shape. Fails on main (expected '0.7.0' not to be '0.7.0').

Neighbor suites (4649-subagent-model-selection, model-registry, 696-empty-codex-catalog): 85/85. Note: two 4649 tests fail on unmodified main when DEEPSEEK_API_KEY/OPENROUTER_API_KEY/HF_TOKEN are set in the environment (provider availability leaks into discovery); all green with those unset, before and after this change. npm run check clean.

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Note

Low Risk
Narrow change to Codex catalog discovery query params plus a regression test; no auth or data-path changes.

Overview
Fixes #702 by stopping openAICodexModelsUrl from sending prime-agent’s package VERSION as the client_version query param on /codex/models requests. The ChatGPT backend treats that as an outdated Codex CLI client and returns an empty catalog, which made every openai-codex model disappear from discovery, getAvailable(), and subagent flows despite valid auth.

The URL builder now uses a pinned OPENAI_CODEX_CLIENT_VERSION (0.146.1) with an inline comment explaining why the app version must not be used; the unused VERSION import is removed from model-registry.ts.

Adds regression test 702-codex-client-version.test.ts, which stubs fetch, runs findRlmModels, and asserts client_version is not the package version and matches a Codex CLI-style semver.

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Note

Fix Codex model discovery to send a pinned Codex CLI version as client_version

The Codex model discovery URL was sending the package VERSION as client_version, but the OpenAI Codex endpoint gates on a specific Codex CLI version. model-registry.ts now uses a hardcoded constant OPENAI_CODEX_CLIENT_VERSION (0.146.1) instead. A regression test verifies the pinned version is sent and differs from the package VERSION.

^{Macroscope summarized 5392c28.}

[sethkarten]

Thank you for the report and proposed work. This root cause is now covered by maintainer-owned stacked PR #1164, authored independently from upstream/main.

We did not inspect or reuse this PR's diff, branch, commits, implementation code, or tests; its public description/comments were used only as a bug report. To keep one review surface, this PR is superseded by #1164 and is being closed.

The complete review stack is #1158–#1165. It is being left unmerged for human review after CI and review-bot findings are cleared.

[ayushnangia]

Thanks for the clear provenance note — understood on report-only usage, and consolidating into the maintainer-owned #1158–#1165 stack makes sense as one review surface. The pinned OPENAI_CODEX_CLIENT_VERSION root cause is exactly the kind of thing I'd want a stack like that to absorb; happy to verify #1164 against my original repro ("expected '0.7.0' not to be '0.7.0'") once it clears CI, if useful.