中转 api 的 gemini-3-pro-image-priview 模型经过测试可以正常画图，并且返回的内容是 base64 图片: 
    {
      "role": "assistant",
      "content": "![image](data:image/jpeg;base64,/9j/4AAQSkZJRgABAQEBLAEsAAD/xx//Z)",
      "createAt": 1770184552571,
      "id": "5",
      "reasoningContent": "**Outlining the Infographic**\n\nI've outlined the infographic's.xxxx.\n\n\n",
      "isReasoningExpanded": false,
      "isThinkingC...