fix “Failed to get agent_messages from the codex session”

[Silentely]

claude调用时会报

"result": {

        "success": false,

        "error": "Failed to get `agent_messages` from the codex session. \n\n You can try to set

    `return_all_messages` to `True` to get the full reasoning information. \n\n 2025-11-28T12:23:06.643222Z ERROR

    rmcp::transport::async_rw: Error reading from stream: serde error data did not match any variant of untagged

    enum JsonRpcMessage"

因为有一段数据混入，导致直接返回False并中断

2025-11-28T11:20:00.13432Z ERROR rmcp::transport::async_rw: Error reading from stream: serde error data did not match any variant of untagged enum JsonRpcMessage

[sczheng189]

有用

[GuDaStudio]

感谢contribution，非常有洞察力的发现，帮助定位了长久以来困扰我们的问题！但当我合并了 #23 后，这里有一些小冲突，可以帮忙rebase一下吗？😀