dsh-plugin-approval-alert: DeepSeek Harness Approval Reminder Plugin

dsh-plugin-approval-alert is an approval alert plugin for DeepSeek Harness, designed to solve the problem of users easily missing approval or scheme selection prompts when the browser is not in the foreground. This pure browser-side plugin is registered in the `shell.overlay` slot and does not interfere with the approval pipeline. When Harness triggers an approval, scheme selection, `ask_user_question`, or scheme review, the plugin displays system-level notifications via the Web Notifications API, displaying the corresponding workspace name and playing a double-beep sound. Notifications support Simplified Chinese, Traditional Chinese, and English; clicking them automatically redirects the browser to the corresponding session. The plugin is compatible with Windows, Linux, and macOS, requiring browser support for the relevant APIs and notification permissions. Installation command: