dsh-plugin-nlbi: Natural Language Queries and BI Reports

`dsh-plugin-nlbi` is a plugin for `DeepSeek Harness`, designed to add natural language query (Text2SQL) and BI reporting capabilities to `dsh-mysql`. It supports generating and executing SQL from natural language, creating visual charts, and providing management tools such as report favorites, data browsing, and an intelligent sidebar workspace. Installation requires Node.js, its functionality is limited to MySQL, and read-only operations are enforced to ensure security.