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.

未指定源文件或测试。请在已安装 plugin 的情况下复现 `/plugin rm superpowers@superpowers-marketplace`，将其与 `/plugin uninstall` 进行比较，并追踪 alias 在哪里被解释以及模型调用在哪里发生。完成的标准是：移除过程无需不必要的帮助查询或 LLM 输入即可完成，并且有测试覆盖此行为。

由索引模型根据 Issue 内容生成。