Allow users to close leased browser tabs without cancelling the AI request or revoking its other tools. Closed-page operations report a recoverable error; explicit navigation creates a dedicated replacement tab for direct-model and MCP calls.
Add regression coverage and real Electron lifecycle checks, and update browser behavior documentation.
Release note: 浏览器标签页被 AI 请求占用时也可关闭,其他任务继续运行;再次导航会打开独立新页。