Cloud session create times out waiting for remote sandbox CLI host

### Short summary

Cloud session creation fails every time with RPC -32603: timed out waiting for the remote sandbox CLI host to connect.

### Affected version or release

GitHub Copilot app 1.1.12 on macOS 26.6.2 (25G83)

### Installation context

GitHub Copilot desktop app. Creating a **Cloud** session against the private repository `Apex-Global-Solutions/ARWorkflow` (default branch `master`). Local/worktree sessions for the same repo work.

The original reporter uses Enterprise Managed User `FLuque_axg` (cannot file on this public repo). Filed from personal account `fabianluque`.

### What happened?

Every attempt to create a new Cloud session fails at approximately the 67-second mark. The client reports that the cloud session was created, but the remote CLI host never connects in time.

Error shown in the app:

```
Session creation failed
Failed to create session: RPC error -32603: Request session.create failed with message: Timed out waiting for the remote sandbox to start. The cloud session was created but its CLI host did not connect in time. Please try again.
```

This is 100% reproducible (every attempt).

### Steps to reproduce

1. Open the GitHub Copilot app (1.1.12) on macOS.
2. Create a new **Cloud** session targeting `Apex-Global-Solutions/ARWorkflow`.
3. Wait for session creation.

### Expected behavior

The cloud session starts and the remote CLI host connects so the session becomes usable.

### Additional context

- Timing is consistent: the error appears around **67 seconds** after starting creation.
- The remote session appears to be created; only the CLI host connection times out.
- Local / worktree sessions continue to work for the same repository.
- Repo includes `.github/workflows/copilot-setup-steps.yml` (sets up .NET from `global.json` and Node.js 20.19).
- GitHub-reported repository size is ~49 MB.
- This is a different failure from an earlier `Failed to create remote session in the cloud: 502` (GitHub Unicorn HTML page) seen on 2026-08-17 during a GitHub outage.

Tái hiện lỗi trong ứng dụng GitHub Copilot 1.1.12 trên macOS bằng repository riêng tư được chỉ định, và so sánh việc tạo các phiên Cloud với các phiên local/worktree. Kiểm tra .github/workflows/copilot-setup-steps.yml và lỗi timeout của remote CLI host đã được báo cáo; hoàn tất khi một phiên Cloud khởi động và CLI host của phiên đó kết nối trước khi timeout.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.