dsh-ui-digest: DeepSeek Harness Session Overview Plugin

`dsh-ui-digest` is a plugin for DeepSeek Harness, designed to improve the readability of long conversation windows. It adds an “Overview” tab to the conversation view, compressing the entire conversation into one line per turn, including the user message, a one-sentence AI summary, and action chips. The tool supports real-time updates and bilingual display, and is zero-cost and fully client-side. Users can click a row to expand and view the full content. Summaries are generated through heuristic extraction, do not rely on an LLM, and strictly follow a read-only projection mode by displaying only the content retained in the current window.