Actions Debugger [GA]

### Value Prop
The Actions Debugger gives developers an interactive way to troubleshoot GitHub Actions workflows in real time, so you can spend less time guessing and more time building. Securely attach to a running job during execution, inspect environment variables, filesystem state, and step outputs with a debug client of your choice, and re-run individual steps without restarting the entire workflow.

### Expected Outcome
By making debugging interactive and efficient, we aim to shorten feedback cycles and reduce the guesswork involved in fixing workflow problems. Developers will be able to quickly validate assumptions, understand failures, and resolve issues, leading to smoother CI/CD workflows and a better overall experience with GitHub Actions.

该 issue 提供了产品描述，但没有指明任何文件、测试或实现入口。首先识别现有的 GitHub Actions workflow 执行和调试组件，然后确定连接到正在运行的 job、检查状态以及重新运行 step 的范围。Done 应与所述的交互式调试结果一致。

由索引模型根据 Issue 内容生成。