dsh-dingtalk: DeepSeek Harness DingTalk Group One-way Notification Plugin

dsh-dingtalk is a community plugin for DeepSeek Harness designed to simplify the process of sending notifications to DingTalk groups after agent tasks are completed. Built on pure Node.js with no runtime dependencies, it supports Windows, macOS, and Linux across all platforms. It encapsulates the DingTalk custom bot webhook, providing two tools: `dingtalk_notify` (for sending Markdown messages) and `dingtalk_text` (for sending plain text messages), and supports signature security mode. Users can install it via the `dsh plugin` command and configure `webhook`, `secret`, and `timeout` in `cordis.patch.yml`.