Add "ultra" reasoning level for Codex GPT-5.6 Sol and Terra, and expose Max for Luna (Luna falls back Ultra to Max since it is not supported upstream). Scoped to cx/ routes only; Kiro and generic OpenAI routing unchanged.
Add "ultra" reasoning level for Codex GPT-5.6 Sol and Terra, and expose Max for Luna (Luna falls back Ultra to Max since it is not supported upstream). Scoped to cx/ routes only; Kiro and generic OpenAI routing unchanged.