Replace execSync with spawnSync

[inkz]

问题描述 | Describe the bug

Currently, the codebase uses child_process.execSync,
https://github.com/Mereithhh/vanblog/blob/master/packages/server/src/utils/deleteFolder.ts#L3
which is vulnerable to command injection, as the user input is passed.

To enhance security, please replace execSync with spawnSync from child_process, which provides better control over argument handling and avoids shell interpretation issues.
e.g.

execSync('rm', ['-rf', p]);

复现网址 | Website URL

版本 | Version

部署方式？ | How do you deploy vanblog?

Docker 部署(文档默认)