DeepSeek Harness (DSH) Plugin: dsh-updater-npm

`dsh-updater-npm` is a plugin that integrates DSH core updates with official documentation management. It features one-click updates via npm, incremental documentation synchronization, search and reading, and multilingual support. The plugin supports two operating modes, npm global and source tree, and provides robust backup and rollback mechanisms along with API interfaces, simplifying the development and operations workflow through unified management.