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

Office document tools (xlsx / pdf / pptx / docx) for DeepSeek Harness: generate, read, and edit spreadsheets, PDFs, presentations, and Word documents

Talk to Excel in DeepSeek Harness: create/edit spreadsheets, formulas, styles, filters, and tables by conversation; auto-verifies formulas after every edit, repairs silent errors, and validates charts.

为 better-sidebar 提供 Office 三件套预览（.docx/.xlsx/.pptx），独立 bundle 瘦身主体 | Provides Office-suite preview (.docx/.xlsx/.pptx) for better-sidebar as a separate bundle to slim the core

向模型暴露 MinerU 文档解析工具，将 PDF/图片/DOCX/PPTX/XLSX 转为结构化 Markdown/JSON | Exposes MinerU document-parsing tools to the model, converting PDF/images/DOCX/PPTX/XLSX into structured Markdown/JSON

DSH web plugin: Office file previewers (.docx/.xlsx/.pptx) for the better-sidebar editor. Registers the docx/xlsx/pptx file viewers through ctx.betterSidebar.registerFileViewer, keeping the heavy Office render libraries (docx-preview / Univer / SheetJS /