OpenAI GPT-5.6 Claude Code cells burn minutes on CLI timeouts under the
full stage suite; gate them behind COMPAT_OPENAI_GPT_CELLS=1 like Mantle.
Multi-window budget e2e used max_tokens=1 which gpt-5.5 rejects mid-message
The openai and azure_openai columns have working credentials in every suite runner, so only the bedrock_mantle column still needs an opt-in flag while the AWS account waits on the Mantle allowlist; COMPAT_GPT_CELLS becomes COMPAT_MANTLE_CELLS. The six tool_use cells now resolve the proxy through claude_code._env like the basic_messaging cells instead of hardcoding LITELLM_PROXY_BASE_URL/LITELLM_PROXY_API_KEY.
