Expand `~` from config

### Is there an existing issue for this?

- [x] I have searched the existing issues

### OS/Web Information

- Web Browser: Vivaldi
- Local OS: Ubuntu 24.10
- Remote OS: Ubuntu 24.10
- Remote Architecture: amd64
- `code-server --version`: 4.93.1 69df01185ce2f80e99c9e4f8c8de1907cc7a9bc5 with Code 1.93.1

### Steps to Reproduce

1. add this `user-data-dir: ~/.config/code-server-data` to config.yaml
2. run command `code-server`

### Expected

```
~/.config/code-server-data
```

### Actual
But in the web browser, it will be:
```
~/~/.config/code-server-data
```
### Note
I get it now, depends on where the current directory in the terminal is, code-server will use the current directory plus user-data-dir

通过在 config.yaml 中设置 user-data-dir: ~/.config/code-server-data，并从不同的当前目录运行 code-server，重现该报告。跟踪配置值的解析方式，然后验证最终的浏览器路径是 ~/.config/code-server-data，而不是重复的路径或带有当前目录前缀的路径。

由索引模型根据 Issue 内容生成。