dsh-paperpanel: A Zotero-Style Library Panel in DSH Web

`dsh-paperpanel` is a DSH web plugin designed to address local file-management pain points and provide a unified Zotero-like interface. It integrates local files through a floating drawer, supporting the browsing, reading, and editing of PDF, Word, Markdown, and spreadsheet files. Core features include centered reading with note-taking on selected passages, a table workspace with charts and backups, and AI API integration. The plugin runs entirely offline; once installed, users can manage various file types from the right side.