dsh-astrbot-ingress: Use AstrBot as an IM Gateway to Drive Local DeepSeek Harness

`dsh-astrbot-ingress` is an HTTP ingress plugin for DeepSeek Harness and AstrBot, maintained by CCYellowStar2. It enables AstrBot to act as an IM gateway and delegate tasks to a local DeepSeek Harness instance for execution. Installation requires adding the plugin on the DSH side and restarting it, while installing `astrbot_plugin_dsh` on the AstrBot side. The plugin supports the OneBot protocol and provides features such as session binding, file transfer, progress reporting, reasoning mode switching, and common commands (e.g., `/dsh`). Users should pay attention to dual-plugin dependencies, token configuration, and file size limits during use.