dsh-event-relay: A Shared SSE Channel for Pushing Host Notifications to the Browser

dsh-event-relay is a shared SSE endpoint solution designed for the DeepSeek Harness plugin, intended to address the communication challenge of notifying the browser side about real-time state changes from the host side. The plugin implements server-side filtering and reconnection signaling through a single route, supporting event publishing from the host and event subscription in the browser. Its core advantages are zero dependencies, avoidance of connection-count limits, and a one-way communication mechanism. Developers can use it as a payload trigger or consume messages directly, and should implement a fallback mechanism to handle cases where the plugin is unavailable.