dsh-literature-hub: Add a local literature library to DeepSeek Harness

Introducing the community plugin dsh-literature-hub: This plugin integrates PDF, DOCX, Markdown, and HTML files from an Obsidian knowledge base into a unified reading interface. It offers features such as annotations, rich-text notes, reading companion sessions, study records, and local Whisper offline transcription. The article provides fixed-version installation commands, vaultPath configuration, a five-minute getting-started guide, applicable scenarios, and permission precautions, and clarifies that the plugin does not connect to the internet and runs with the current dsh process permissions.