Kimi K2.7 Code keeps stopping after thinking without doing the work

### Short summary

Kimi K2.7 Code from GitHub Copilot keeps stopping without doing the actual work

### Affected version or release

v1.0.18

### Installation context

_No response_

### What happened?

We've enabled Kimi K2.7 code in GitHub Copilot Enterprise, and while it kind of works, it frequently stops right after thinking without taking the action you'd expect it to do. This doesn't happen with other models like GPT 5.5 or MAI-Code-1-Flash. I suspect Kimi K2.7 Code signals something that makes GitHub Copilot think its done and should stop when it really shouldn't. This makes the model unusable most of the time, because when it refuses to just do the thing, it won't budge and I have to switch to another model to ask it to do something.

### Steps to reproduce

Ask a simple query like "open a pull request" or "watch the workflow run". It will show brief thinking, and then it'll stop. If you look at the thinking details, it shows it understood what the action to be taken is, except it doesn't do it. Repeatedly asking for the same thing doesn't help.

### Expected behavior

When asking Kimi K2.7 Code to do something, I would expect to do the action instead of stopping, like all other models.

### Additional context

まず、"open a pull request" または "watch the workflow run" を使って、GitHub Copilot Enterprise と Kimi K2.7 Code で v1.0.18 の問題を再現し、その後、GPT 5.5 または MAI-Code-1-Flash と動作を比較します。完了の条件は、思考フェーズの後に停止するのではなく、要求されたアクションが実行されることです。

索引モデルが issue の本文から書いたものです。