Copy the prepared DS node_modules contents directly so electron-builder retains the CLI entry and nested Web assets. Fail portable output validation when the DS entry is absent, preventing browser launch from failing with ENOENT.
Add regression coverage using the actual builder matcher and include the pending Continue/OpenCode article screenshots.
Validation: 3 focused packaging tests passed; staged whitespace checks passed. No new full-suite or remote Host validation was performed for this commit.
Release note: 修复 Windows portable 包遗漏 DS Web 依赖导致无法在浏览器中打开的问题；构建时会检查启动入口是否完整。
