Updated the builtin `codex-oauth/gpt-5.5` entry so `context_window = 272000` directly represents the effective Codex OAuth / ChatGPT backend route limit, with a catalog comment explaining that generic OpenAI docs advertise 1.05M. Removed catalog-level `max_context_window` from that entry while preserving inline/config `max_context_window` support. External review approved and validation passed.
