Automated DOCX Redlining Engine

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

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 /