dsh-auto-exit: Automatically Exit the CLI Process When Closing the Web UI

`dsh-auto-exit` is a plugin for DSH `--profile web` mode, designed to resolve the issue where closing the Web UI does not stop the CLI process. It detects WebSocket connections to automatically exit after all browser tabs are closed (equivalent to Ctrl+C). It supports a grace period, status checking, and various configurations, preventing accidental exits caused by sleep or page refreshes.