[bug]: hook example `GpCodeReview` sends to wrong endpoint

[kunzaatko]

The hook calls get_chat_agent(). With get_command_agent() it works correctly but when using Prompt, it calls the wrong endpoint. Even though, I am using claude sonnet, I am getting the response from the openai endpoint.

Here is the error:

Gp: openai response is empty:
'{\n    "error": {\n        "message": "The model `claude-3-5-sonnet-20240620` does not exist or you do not have access to it.",\n        "type": "invalid_request_error",
\n        "param": null,\n        "code": "model_not_found"\n    }\n}\n'

Here is the reference hook from the README:

        -- GpCodeReview: Review the provided selection/range
        CodeReview = function(gp, params)
          local agent = gp.get_chat_agent()
          local template = 'I have the following code from {{filename}}:\n\n'
            .. '```{{filetype}}\n{{selection}}\n```\n\n'
            .. 'Please analyze for code smells and suggest improvements.'
          gp.Prompt(params, gp.Target.enew 'markdown', nil, agent.model, template, agent.system_prompt)
        end,

Note that the same problem is with GpExplain.
I would try to debug myself, but I am not sure what the intention is for get_command_agent and get_chat_agent and whether the latter should be used in some hooks...