The chat_completions chokepoint fix (ultra->max for every model,
cherry-picked from #89509) has siblings with the same bug shape:
- codex.py: ultra->max was gated on gpt-5.6 only; now baseline for all
Responses-API models (backend-specific branches still override).
- Kimi top-level reasoning_effort: K3 accepts low/high/max only —
'medium' and upper-ladder levels were dropped to the medium default
(400s on K3, ladder inversion on K2). Full ladder mapped per family,
mirroring the kimi-coding plugin's K3 map.
- TokenHub: 'minimal' fell through to the 'high' default (asked least,
got most); full ladder now mapped onto low/medium/high.
- auxiliary_client Responses path: ultra->max alongside the existing
minimal->low clamp.
- custom provider plugin: ultra capped at max instead of forwarded
verbatim to GLM/vLLM/SGLang backends that reject it.
- copilot plugin: ad-hoc downgrade rules replaced with the shared
clamp_reasoning_effort_to_supported ladder walk so ultra/max resolve
to the strongest supported level instead of medium (#74295).
Sabotage-verified: new sibling-site tests fail 6/10 without the fixes.
9ec5750aca