浏览器插件增加state命令，方便编写脚本时定位元素 adds state command to extension

[liqt91]

描述

为扩展添加 state 命令，用于查看当前页面的元素序号。

变更类型

• 🐛 Bug 修复
• ✨ 新功能
• 🌐 新站点适配器
• 📝 文档
• ♻️ 重构
• 🔧 CI / 构建 / 工具

检查清单

• 我已运行相关检查
• 我已更新测试或文档（如需要）
• 我已附上输出或截图（如有用）

[freemandealer]

sexy feature 👍 I'll test it

[freemandealer]

Just tested it. It works great! except for the following two problems/potential enhancements:

1. An 'OFF' button should be provided to hide the labels
2. The browser window won't auto-close after the idle timeout any more

[jackwener]

Closing as stale/superseded by current main.

I checked this against the current code rather than just the PR title. The proposed browser state command is already present on main: the browser command group is registered in src/cli.ts, and src/cli.ts:939 already defines browser.command('state') with the same user-facing contract (page state / interactive element indices). The current docs also expose it (README.md and docs/developer/ai-workflow.md).

Since the feature this PR adds is already on main through later work, this branch is stale and no longer needs to merge as-is.