dsh-modular-scale: Font Size Scale and Modular Scale Calculator

`dsh-modular-scale` is a DeepSeek Harness (DSH) plugin designed to eliminate the tedious manual calculation of type scales and modular ratios when agents generate typography. It provides type scale and modular ratio calculation capabilities, supporting user-defined ratios (e.g., 1.2 or 1.618). After installation, it must be enabled in the `package.json` configuration file. Since it is a pure Node.js implementation, users should review the source code and license on their own before use.