feat: enhance desktop packaging process with self-contained harness verification

- Updated README and README.zh to clarify packaging commands and added verification step.
- Improved packaging scripts to automatically build the self-contained runtime and verify its integrity.
- Introduced new scripts for verifying harness self-containment and booting the web profile.
- Added comprehensive tests for relinking harness symlinks and ensuring self-containment.
- Updated package.json scripts to reflect new build and verification processes.

README.zh.md

@@ -102,8 +102,8 @@ pnpm desktop:dev        # 打开桌面窗口
 ### 打包发布
 
 ```sh
-pnpm --filter @deepseek-ai/dsh-desktop run build:harness   # 组装自包含运行时
-pnpm desktop:pack                                          # electron-builder:.dmg / .nsis
+pnpm desktop:pack                                          # 构建 lib+web,组装自包含 harness,再 electron-builder:.dmg / .nsis
+pnpm desktop:verify                                        # 证明打包后 app 内的 harness 完全自包含且能启动
 pnpm --filter @deepseek-ai/dsh-desktop run stage-release   # 将安装包 + 清单拷入发布站
 ```