[BUG] /context in Claude Code for VS Code causes request spikes and may trigger rate limits or DoS protection

### Preflight Checklist

- [x] I have searched [existing issues](https://github.com/anthropics/claude-code/issues?q=is%3Aissue%20state%3Aopen%20label%3Abug) and this hasn't been reported yet
- [x] This is a single bug report (please file separate reports for different bugs)
- [x] I am using the latest version of Claude Code

### What's Wrong?

When using the `/context` command in Claude Code for VS Code, a large number of requests are generated within a short period. This easily triggers API rate limiting and may even get blocked due to false detection of a DoS attack.

In version 3.4, I observed a sudden surge in request volume upon executing this command, which disrupts normal usage.

### What Should Happen?

The `/context` command should operate without triggering an abnormal request storm and should avoid sending excessive requests to the API within a short time frame. Even when gathering context, it must not result in rate limiting or security-based blocking.

### Error Messages/Logs

```shell

```

### Steps to Reproduce

1. Use Claude Code for VS Code, version 3.4.
2. Run the `/context` command.
3. Observe a significant spike in network requests/traffic within a short period.
4. This may trigger API rate limits, or get flagged and blocked by security systems as suspected DoS activity.
5. The attached screenshot illustrates the sharp surge in data volume when executing this command.

### Claude Model

Sonnet (default)

### Is this a regression?

No, this never worked

### Last Working Version

3.4 之前的版本

### Claude Code Version

3.4

### Platform

Other

### Operating System

macOS

### Terminal/Shell

Terminal.app (macOS)

### Additional Information

补充说明：问题主要发生在 Claude Code for VS Code 场景下；图中可见 `/context` 执行期间请求/流量在短时间内显著飙升。希望能优化 `/context` 的请求节流、批处理或缓存策略。

No source file or test is named. Start by reproducing `/context` in Claude Code for VS Code 3.4 on macOS and measure the request spike; done means the command no longer sends excessive requests or triggers rate limiting and DoS protection.

索引モデルが issue の本文から書いたものです。