AI Credit Usage for uninstalling a plugin.

### Describe the bug

Today I removed the superpowers plugin from the superpowers marketplace using `/plugin rm superpowers@superpowers-marketplace` and in order to do so, it needed to read the plugin help, and convert rm alias to the uninstall command.

I don't understand why this is not just an alias that performs the exact same command.

Instead it used 8.83 AI Credits. 0.126% of my 7000 allowance.

### Affected version

GitHub Copilot CLI 1.0.68

### Steps to reproduce the behavior

With the plugin installed:
/plugin rm superpowers@superpowers-marketplace

Watch it think:

```
Thought for 1s
The user is trying to uninstall a plugin called "superpowers@superpowers-marketplace" and I need to figure out what CLI command handles plugin removal in this copilot system.

Shell Remove superpowers plugin 2 lines…
copilot plugin rm superpowers@superpowers-marketplace 2>&1

Thought for 1s
I'm wondering if "plugin rm" is actually a subcommand within the Copilot CLI's interactive session rather than something to execute directly through PowerShell. Let me check the help documentation to clarify.

$ Shell Check plugin command help 28 lines…
copilot plugin --help 2>&1
$ Shell Uninstall superpowers plugin 2 lines…
copilot plugin uninstall superpowers@superpowers-marketplace 2>&1
```

Be shocked and amazed at the ridiculousness of this.

### Expected behavior

Use NO input tokens. It is the /plugin command, why does it need to send that to the LLM?

### Additional context

Claude Sonnet 5 (medium) was the selected model.

I had used /plugin list to allow me to copy-paste the plugin name, so it is possible some of the credit usage was from this.

ソースファイルもテストも指定されていません。Plugin をインストールした状態で `/plugin rm superpowers@superpowers-marketplace` を再現し、`/plugin uninstall` と比較して、エイリアスがどこで解釈され、モデル呼び出しがどこで行われるかを追跡してください。削除が不要なヘルプ検索や LLM 入力なしで完了し、この動作をカバーするテストがあれば完了です。

索引モデルが issue の本文から書いたものです。