Title: /allow-all does not suppress bash tool execution prompts

### Describe the bug

### Describe the bug
After running `/allow-all`, the CLI still shows a permission dialog
("Do you want to run this command?") for every bash/shell tool call.

### Steps to reproduce
1. Launch `copilot`
2. Run `/allow-all`
3. Ask Copilot anything that triggers a shell command
4. Permission dialog still appears for each command

### Expected behavior
No prompts after `/allow-all` — all tools, paths, and URLs should be
pre-approved for the session.

### Actual behavior
Every bash tool call still requires manual approval. `/reset-allowed-tools`
followed by `/allow-all` does not fix it.

### Workaround
Use native built-in tools (view, grep, glob) instead of bash where possible.

### Environment
- OS: macOS

### Affected version

GitHub Copilot CLI 1.0.35.

### Steps to reproduce the behavior

1. Launch `copilot`
2. Run `/allow-all`
3. Ask Copilot anything that triggers a shell command
4. Permission dialog still appears for each command

### Expected behavior

No prompts after `/allow-all` — all tools, paths, and URLs should be
pre-approved for the session.

### Additional context

### Actual behavior
Every bash tool call still requires manual approval. `/reset-allowed-tools`
followed by `/allow-all` does not fix it.

### Workaround
Use native built-in tools (view, grep, glob) instead of bash where possible.

### Environment
- OS: macOS

首先，在 macOS 上使用 1.0.35 版本的 copilot CLI 重現此行為：執行 /allow-all，然後觸發一次 bash 或 shell 工具呼叫。追蹤 shell 工具的權限處理，並確認 /reset-allowed-tools 後執行 /allow-all 的情況已涵蓋。完成標準是：在工作階段期間，shell 工具呼叫不再顯示核准提示。

由索引模型根據 Issue 內容生成。