dsh-music-common: Music Theory Basics Plugin

`dsh-music-common` is a plugin for DeepSeek Harness (DSH) that provides foundational music theory data for model inference, with a focus on learning plans for Chinese traditional instruments. It is maintained by developer uckkk and registers the `music_common` tool to return instrument learning plans in a parameterized form. Built with pure Node.js, it makes no network requests and runs efficiently and stably. Install it with `dsh plugin add github:uckkk/dsh-music-common`; the tool is automatically enabled after installation. It is open-sourced under the MIT License.