When a Codex OAuth refresh token is permanently invalidated (HTTP 400/401/403,
token revoked or reused), _mark_exhausted was called but auth.json was left with
the dead credentials. On the next session, _seed_from_singletons re-read
auth.json and re-seeded the pool with the same revoked token, triggering the
same terminal failure in a loop.
Add _is_terminal_codex_oauth_refresh_error to auth.py and a matching quarantine
block in _refresh_entry: when a terminal error is detected and auth.json holds
no newer tokens, clear access_token/refresh_token from auth.json and remove all
device_code-sourced pool entries from memory. Mirrors the Nous quarantine added
in c90556262 and the xAI quarantine in #28116.
Also add a pre-refresh sync from auth.json before calling refresh_codex_oauth_pure,
matching the xAI and Nous patterns, to avoid refresh_token_reused races when
multiple Hermes processes share the same auth.json singleton.
Salvaged from #27911 by @EloquentBrush0x — contributor's branch was severely
stale (would have reverted ~5000 LOC across azure/kanban/i18n subsystems);
fix re-applied surgically on current main with their predicate and tests preserved.
EloquentBrush0x
b570e0fdd0