OpenAI: GPT-5.1-Codex-Mini

curl https://api.vega.chat/api/v1/chat/completions \
  -H "Authorization: Bearer $VEGA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-5.1-codex-mini",
    "messages": [
      {"role": "user", "content": "Hello!"}
    ]
  }'