dsh-kb-sync: DeepSeek Harness Plugin

The DeepSeek Harness (DSH) plugin orchestrates a pipeline that synchronizes web history into a local knowledge base. It supports custom commands, status and log viewing, integrity health checks, incremental or full conversation retrieval, knowledge base search, and script execution. Dependency-free and requiring Node.js ≥ 20, it stores tokens in memory and splits execution in two to enhance security. Users can paste the token on the control page to run synchronization, retrieval, and other operations.