Copilot: Run Code Review: TypeError: Cannot read properties of undefined (reading 'files')

- Copilot Chat Extension Version: Don't know how to extract this. Seems Copilot itself can't
- VS Code Version: `1.134.0`
- OS Version: `Ubuntu 24.04.4 LTS (WSL)`
- Feature (e.g. agent/edit/ask mode): `Chat: Run Code Review`
- Selected model (e.g. GPT 4.1, Claude 3.7 Sonnet): `Auto`
- Logs:

```plain
2026-08-24 15:48:10.064 [error] TypeError: Cannot read properties of undefined (reading 'files')
at Axr (/home/loganmzz/.vscode-server/bin/110a328ea54b42367b803ec53ee0bf52ef26b419/extensions/copilot/dist/extension.js:3203:6755)
at process.processTicksAndRejections (node:internal/process/task_queues:104:5)
at async df._executeContributedCommand (file:///home/loganmzz/.vscode-server/bin/110a328ea54b42367b803ec53ee0bf52ef26b419/out/vs/workbench/api/node/extensionHostProcess.js:544:48874): Error during code review command
```

Steps to Reproduce:

1. Open Command-Palette
2. Select `Chat: Run Code Review`