[BOT ISSUE] OpenAI: add missing gpt-5.6-cyber model

[github-actions]

Summary

The model gpt-5.6-cyber is listed on OpenAI's models page, pricing page, and has a dedicated detail page, but is not present in the Braintrust proxy model catalog.

GPT-5.6 Cyber is a specialized model in the GPT-5.6 family designed for cybersecurity applications. It supports text and image input, text output, reasoning tokens, and has a 400K context window (272K input / 128K output). It is available via the Responses API (v1/responses).

Verification checklist

• Cross-source: Model ID confirmed on OpenAI models page, pricing page, and dedicated detail page (3 independent official sources)
• Already-fixed check: Grepped model_list.json for gpt-5.6-cyber — no match found; searched closed issues — no prior issue exists
• ID format check: gpt-5.6-cyber follows the established OpenAI naming convention (matches sibling gpt-5.6-sol already in catalog)

Proposed catalog entry

{
  "gpt-5.6-cyber": {
    "format": "openai",
    "flavor": "chat",
    "multimodal": true,
    "input_cost_per_mil_tokens": 12.5,
    "output_cost_per_mil_tokens": 75,
    "input_cache_read_cost_per_mil_tokens": 1.25,
    "input_cache_write_cost_per_mil_tokens": 15.625,
    "displayName": "GPT-5.6 Cyber",
    "reasoning": true,
    "max_input_tokens": 272000,
    "max_output_tokens": 128000,
    "available_providers": ["openai"]
  }
}

Sources

• OpenAI models page: https://developers.openai.com/docs/models
• OpenAI pricing page: https://developers.openai.com/docs/pricing
• OpenAI model detail page: https://developers.openai.com/docs/models/gpt-5.6-cyber

[github-actions]

Autofix skipped because the issue body/title did not contain parseable bot metadata for a model catalog change.