* test(e2e): add enum values, auto-discovering label gates and secret hiding for e2e metadata
* test(e2e): tag claude_code tests with Subject metadata and record CLI driver steps
* docs(e2e): name every markerless harness test file that carries no Subject
* test(e2e): keep the step discovery comprehensions to one for clause
* test(e2e): decorate run_claude directly so the label gate discovers its step
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.
