The connection Test button always reported success for a Codex connection
backed by a ChatGPT account: the probe sent `gpt-5.3-codex`, a codex-only
model the ChatGPT-account backend rejects outright with a 400 — the same
status the probe treats as 'auth accepted, body invalid'. A bad token and a
good token both came back 400, so Test could never fail on a bad token.
Probe with `gpt-5.5` (confirmed served for ChatGPT-account sessions via live
VPS test 2026-07-16) instead; `input: []` still yields the intended 400 for a
good token, 401/403 for a bad one.
Live verification (VPS): gpt-5.3-codex, gpt-5.6-sol and the gpt-5*-codex ids all
return 'not supported when using Codex with a ChatGPT account'; gpt-5.5 and
gpt-5.6-terra answer normally on the same account.
Closes#7521
Release v3.8.33 — full CHANGELOG in the PR body. Blocking gates green (Build, Lint, Unit Tests 8/8, Package Artifact, Quality Gates, Quality Ratchet, Docs Sync, PR Test Policy, test-vitest). Admin-merged over a Node 26 future-compat timer flake (1/4) + an E2E UI flake (3/9) — both verified non-deterministic; full test:unit validated locally (16936 pass).
