Code Review panel layout becomes corrupted, and closing tabs can crash the application

### Short summary

_No response_

### Affected version or release

1.0.24

### Installation context

_No response_

### What happened?

I've encountered a UI/layout issue in the Copilot App that sometimes leads to an application crash.

After opening a Code Review (or similar review view), the right-hand panel occasionally becomes completely corrupted. Instead of rendering normally, multiple sections overlap each other, making the content unreadable.

The attached screenshot shows the issue clearly:

Headers overlap with issue descriptions.
Multiple review items are rendered on top of each other.
Text from different sections is mixed together.
Scrolling does not restore the layout.

In addition, after this corrupted state occurs, closing certain tabs (such as the Code Review tab or other related tabs) can cause the entire Copilot App to crash unexpectedly.

### Steps to reproduce

_No response_

### Expected behavior

The review panel should render each issue in its own layout without overlapping.
Closing tabs should never crash the application.

### Additional context

まず、Code Review ビューを開いた後の Copilot App バージョン 1.0.24 で問題を再現します。添付されたスクリーンショットを想定される失敗状態として使用してください。review パネルのレイアウトと、Code Review または関連するタブを閉じる処理を調査します。review 項目が重なりなく表示され、タブを閉じてもアプリケーションがクラッシュしなければ完了です。

索引モデルが issue の本文から書いたものです。