Permission prompts should display the specific rule or command characteristic that triggered approval

### Describe the feature or problem you'd like to solve

When GitHub Copilot CLI requests permission to execute a command, the prompt does not explain which specific part of the command triggered the safeguard. This makes it difficult to understand why approval is required, evaluate whether the safeguard is behaving correctly, and tune AI behavior to avoid triggering a permission prompt

### Proposed solution

Display the specific permission rule(s) or command characteristic(s) that triggered the approval requirement.

### Example prompts or workflows

### Example 1
Command:
```Remove-Item -Recurse .\temp```

Reason: Uses `Remove-Item`

### Example 2
Command:
```cp file.txt ../other-project/```

Reason: Writes outside trusted directory

### Example 2
Command:
```cp file.txt ../other-project/```

Reason: Writes outside trusted directory

### Example 3
Command:
```Get-Content "$logPath"```

Reason: Uses string interpolation

### Additional context

Other agent-based coding tools surface the specific action that triggered a permission request. This provides:
- Better transparency
- Greater user trust
- Easier debugging of unexpected prompts
- Improved understanding of permission boundaries
- Better feedback when safeguards are overly broad or overly sensitive

Without this information, users are left guessing which command characteristic caused the approval request and cannot easily determine whether the safeguard behaved as intended.

Start at the Copilot CLI permission-prompt and command-safeguard entry points; trace how approval requests are created for the Remove-Item, cp, and Get-Content examples. Done means each prompt identifies the rule or command characteristic that triggered it, with coverage for the stated workflows.

Written by the indexing model from the issue text.