Support gpt models for Copilot

[nighca]

Confirm that gpt-5 functions correctly for Copilot, and if so, set it as the default model.

[nighca]

API incompatibility introduced by openai/gpt-5:

• max_tokens -> max_completion_tokens

• temperature 0.7 is not supported

  Unsupported value: 'temperature' does not support 0.7 with this model. Only the default (1) value is supported. (type: invalid_request_error)
  

[nighca]

Other problems introduced by openai/gpt-5:

1. Slow response

Can be optimized by setting ReasoningEffort.

• ReasoningEffort: minimal: The quickest, quicker than Claude 4.0 Sonnet, while more stupid.
• ReasoningEffort: low: similar time cost to Claude 4.0 Sonnet.

2. Random incorrect answer: response got for previous request

For request with non-tutorial messages, response for tutorial course is returned.

Request messages: messages.json

Response:

你好！我们来给精灵“播放”加一个声音，并在点击时播放它。

步骤：
1) 先添加一个声音到项目
- 点击这里打开声音面板，然后添加一个声音文件（记住它的名字，建议命名为 s1）：<highlight-link target-id="xp2enODt" tip="打开声音面板，添加一个声音文件（如命名为 s1）">打开声音面板</highlight-link>

2) 在“播放.spx”代码里添加点击事件播放声音
- 从左边 API 参考把这两个积木拖到代码编辑器：
- <highlight-link target-id="5sXOshEf" tip="拖到代码编辑器，添加点击事件">onClick =&gt; {}</highlight-link>
- <highlight-link target-id="G5Ayv4rm" tip="拖到 onClick 里面，播放声音">play "s1"</highlight-link>
- 如果你的声音不是叫 s1，把 "s1" 改成你刚添加的声音名。

你也可以一键应用下面的代码到“播放.spx”：
<code-change file="播放.spx" line="1">
onClick =&gt; {
    play "s1"
}
</code-change>

3) 运行测试
- 点击这里运行项目：<highlight-link target-id="Mu8t6w0m" tip="运行项目，点击精灵试试是否能播放声音">运行</highlight-link>

需要我帮你把声音名字替换到代码里吗？告诉我你添加的声音名称就行。

3. Passing attributes of custom-elements with camel-case name (kebab-case expected).

[nighca]

4. Prefer to include more steps in one message

Even we already told it not to and examples were provided for that.

GPT-5 (resoning-effort: low):

Claude 4.5 Sonnet:

[nighca]

Due to the need for additional compatibility and prompt-tuning efforts, we will postpone this attempt and continue using Claude 4.0/4.5 Sonnet fow now.