Description / 描述

Fixed sed command syntax in build.sh to support both macOS (BSD sed) and Linux/Windows (GNU sed) environments. The script now detects the operating system using $OSTYPE and applies the appropriate sed syntax when updating package.json version during dev builds.

修复了 build.sh 中的 sed 命令语法，使其同时支持 macOS（BSD sed）和 Linux/Windows（GNU sed）环境。脚本现在通过 $OSTYPE 检测操作系统，并在开发构建更新 package.json 版本时应用相应的 sed 语法。

Changes / 改动:

• Added OS detection for macOS (darwin*)
• macOS: Uses sed -i "" (BSD sed syntax)
• Linux/Windows: Uses sed -i (GNU sed syntax)

Motivation and Context / 背景

The original sed -i command without an empty string argument works on Linux/Windows but fails on macOS because macOS uses BSD sed, which requires either sed -i "" or sed -i .bak.

原始的 sed -i 命令在 Linux/Windows 上可以正常工作，但在 macOS 上会失败，因为 macOS 使用 BSD sed，需要使用 sed -i "" 或 sed -i .bak 语法。

This caused build failures for developers working on macOS when running dev builds.

这导致在 macOS 上工作的开发者运行开发构建时出现失败。

How Has This Been Tested? / 测试

• ✅ Tested on macOS (darwin) - sed -i "" syntax works correctly
• ✅ Verified code logic for Linux (linux-gnu) - uses sed -i
• ✅ Verified code logic for Windows Git Bash (msys) - uses sed -i
• ✅ Verified code logic for Windows WSL (linux-gnu) - uses sed -i

在 macOS 上测试通过，并验证了 Linux 和 Windows 环境的代码逻辑。

Checklist / 检查清单

• I have read the CONTRIBUTING document.
  我已阅读 CONTRIBUTING 文档。

• I have formatted my code with go fmt or prettier.
  我已使用 go fmt 或 prettier 格式化提交的代码。

• I have added appropriate labels to this PR (or mentioned needed labels in the description if lacking permissions).
  我已为此 PR 添加了适当的标签（如无权限或需要的标签不存在，请在描述中说明，管理员将后续处理）。

  **Suggested labels / 建议标签:** `bug`, `build`
  

• I have requested review from relevant code authors using the "Request review" feature when applicable.
  我已在适当情况下使用"Request review"功能请求相关代码作者进行审查。

• I have updated the repository accordingly (If it's needed).
  我已相应更新了相关仓库（若适用）。

  • OpenList-Frontend - This PR
  • OpenList-Docs - Not needed