dsh-sidebar-onlyoffice: Real-Time Document Editing Plugin for the DeepSeek Harness Sidebar

`dsh-sidebar-onlyoffice` is a plugin that embeds the ONLYOFFICE document editor into the DeepSeek Harness (DSH) sidebar, designed to meet the need for real-time collaboration and in-depth editing in agent development. It supports true editing of .docx, .xlsx, and .pptx files, and features core capabilities such as a same-origin proxy to resolve cross-origin issues, HS256-JWT security configuration, and real-time push refresh for AI-modified content. Through atomic saving, self-save suppression, and in-network communication mechanisms, it effectively addresses risks of editor state desynchronization and data loss, achieving a complete closed loop from read-only preview to real-time editing.