Pluggable DeepSeek-colored TUI for DeepSeek Harness

专门为 agent 打造的 agent 搜索工具，具备多语言搜索能力，覆盖中文/英文/学术/代码/购物/金融/新闻/百科。

DeepSeek Harness dual-face plugin: session-isolated file upload with colorful composer cards + read_document tool (text/PDF/DOCX/XLSX) with content sniffing and LRU caching