在新版ComfyUI中无法手动修复python lib

### Prerequisites

- [x] I am running the latest version of ComfyUI
- [x] I have custom nodes enabled

### What happened?

我的.venv库出现了错误，我无法找到问题，当我删除整个.venv时发现没有找到重新下载的选项，这对我非常不便

### Steps to Reproduce

null

### How is this affecting you?

Feature doesn't work as expected

### ComfyUI Frontend Version

1.0.13

### Browser

Edge

### Console Errors

```javascript

```

### Logs

```shell

```

### Additional Context

_No response_

No source file, test, entry point, reproduction steps, or logs are provided. Start by reproducing the missing recovery flow after deleting or corrupting the .venv, then trace how the frontend handles Python-library setup. Done means a user can recover the environment in the current ComfyUI version without manually rebuilding it.

Written by the indexing model from the issue text.