Vertex AI渠道claude code格式转换无法正常工作

[XTFG]

Routine Checks

• [x] I have confirmed there are no similar issues currently
• [x] I have confirmed I have upgraded to the latest version
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• [x] I understand and am willing to follow up on this issue, assist with testing and provide feedback
• [x] I understand and acknowledge the above, and understand that project maintainers have limited time and energy, issues that do not follow the rules may be ignored or closed directly

Issue Description

在newapi中正确配置Vertex AI渠道后使用标准v1/messages接口接入Claude Code，自动格式转换无法正常运行，报错信息中可以观察到明显的Anthropic格式特有的input_schema字段，疑似将Anthropic 原生格式请求未转换直接透传给下游Vertex AI

报错信息：

    Cannot find field.\nInvalid JSON payload received. Unknown name \"max_tokens\": Cannot find field.\nInvalid JSON
    payload received. Unknown name \"messages\": Cannot find field.\nInvalid JSON payload received. Unknown name
    \"system\": Cannot find field.\nInvalid JSON payload received. Unknown name \"temperature\": Cannot find
    field.\nInvalid JSON payload received. Unknown name \"thinking\": Cannot find field.\nInvalid JSON payload received.
     Unknown name \"description\" at 'tools[0]': Cannot find field.\nInvalid JSON payload received. Unknown name
    \"input_schema\" at 'tools[0]': Cannot find field.\nInvalid JSON payload received. Unknown name \"name\" at
    'tools[0]': Cannot find field.\nInvalid JSON payload received. Unknown name \"description\" at 'tools[1]': Cannot
    find field.\nInvalid JSON payload received. Unknown name \"input_schema\" at 'tools[1]': Cannot find field.\nInvalid
     JSON payload received. Unknown name \"name\" at 'tools[1]': Cannot find field.\nInvalid JSON payload received.
    Unknown name \"description\" at 'tools[2]': Cannot find field.\nInvalid JSON payload received. Unknown name
    \"input_schema\" at 'tools[2]': Cannot find field.\nInvalid JSON payload received. Unknown name \"name\" at
    'tools[2]': Cannot find field.\nInvalid JSON payload received. Unknown name \"description\" at 'tools[3]': Cannot
    find field.\nInvalid JSON payload received. Unknown name \"input_schema\" at 'tools[3]': Cannot find field.\nInvalid
     JSON payload received. Unknown name \"name\" at 'tools[3]': Cannot find field.\nInvalid JSON payload received.
    Unknown name \"description\" at 'tools[4]': Cannot find field.\nInvalid JSON payload received. Unknown name
    \"input_schema\" at 'tools[4]': Cannot find field.\nInvalid JSON payload received. Unknown name \"name\" at
    'tools[4]': Cannot find field.\nInvalid JSON payload received. Unknown name \"description\" at 'tools[5]': Cannot
    find field.\nInvalid JSON payload received. Unknown name \"input_schema\" at 'tools[5]': Cannot find field.\nInvalid
     JSON payload received. Unknown name \"name\" at 'tools[5]': Cannot find field.\nInvalid JSON payload received.
    Unknown name \"description\" at 'tools[6]': Cannot find field.\nInvalid JSON payload received. Unknown name
    \"input_schema\" at 'tools[6]': Cannot find field.\nInvalid JSON payload received. Unknown name \"name\" at
    'tools[6]': Cannot find field.\nInvalid JSON payload received. Unknown name \"description\" at 'tools[7]': Cannot
    find field.\nInvalid JSON payload received. Unknown name \"input_schema\" at 'tools[7]': Cannot find field.\nInvalid
     JSON payload received. Unknown name \"name\" at 'tools[7]': Cannot find field.\nInvalid JSON payload received.
    Unknown name \"description\" at 'tools[8]': Cannot find field.\nInvalid JSON payload received. Unknown name
    \"input_schema\" at 'tools[8]': Cannot find field.\nInvalid JSON payload received. Unknown name \"name\" at
    'tools[8]': Cannot find field.\nInvalid JSON payload received. Unknown name \"description\" at 'tools[9]': Cannot
    find field.\nInvalid JSON payload received. Unknown name \"input_schema\" at 'tools[9]': Cannot find field.\nInvalid
     JSON payload received. Unknown name \"name\" at 'tools[9]': Cannot find field.\nInvalid JSON payload received.
    Unknown name \"description\" at 'tools[10]': Cannot find field.\nInvalid JSON payload received. Unknown name
    \"input_schema\" at 'tools[10]': Cannot find field.\nInvalid JSON payload received. Unknown name \"name\" at
    'tools[10]': Cannot find field.\nInvalid JSON payload received. Unknown name \"description\" at 'tools[11]': Cannot
    find field.\nInvalid JSON payload received. Unknown name \"input_schema\" at 'tools[11]': Cannot find
    field.\nInvalid JSON payload received. Unknown name \"name\" at 'tools[11]': Cannot find field.\nInvalid JSON
    payload received. Unknown name \"description\" at 'tools[12]': Cannot find field.\nInvalid JSON payload received.
    Unknown name \"input_schema\" at 'tools[12]': Cannot find field.\nInvalid JSON payload received. Unknown name
    \"name\" at 'tools[12]': Cannot find field.\nInvalid JSON payload received. Unknown name \"description\" at
    'tools[13]': Cannot find field.\nInvalid JSON payload received. Unknown name \"input_schema\" at 'tools[13]': Cannot
     find field.\nInvalid JSON payload received. Unknown name \"name\" at 'tools[13]': Cannot find field.\nInvalid JSON
    payload received. Unknown name \"description\" at 'tools[14]': Cannot find field.\nInvalid JSON payload received.
    Unknown name \"input_schema\" at 'tools[14]': Cannot find field.\nInvalid JSON payload received. Unknown name
    \"name\" at 'tools[14]': Cannot find field.\nInvalid JSON payload received. Unknown name \"description\" at
    'tools[15]': Cannot find field.\nInvalid JSON payload received. Unknown name \"input_schema\" at 'tools[15]': Cannot
     find field.\nInvalid JSON payload received. Unknown name \"name\" at 'tools[15]': Cannot find field.\nInvalid JSON
    payload received. Unknown name \"description\" at 'tools[16]': Cannot find field.\nInvalid JSON payload received.
    Unknown name \"input_schema\" at 'tools[16]': Cannot find field.\nInvalid JSON payload received. Unknown name
    \"name\" at 'tools[16]': Cannot find field.\nInvalid JSON payload received. Unknown name \"description\" at
    'tools[17]': Cannot find field.\nInvalid JSON payload received. Unknown name \"input_schema\" at 'tools[17]': Cannot
     find field.\nInvalid JSON payload received. Unknown name \"name\" at 'tools[17]': Cannot find field. (request id:
    20251125"},"type":"error"}

Steps to Reproduce

配置Vertex AI渠道后使用标准v1/messages接口接入Claude Code观察api请求报错

Expected Result

希望在Vertex AI渠道添加Anthropic格式请求转换开关以满足将gemini格式模型接入claude code的需求