dsh-option-intrinsic: Option Intrinsic Value Calculation Plugin

The DeepSeek Harness plugin `dsh-option-intrinsic` is designed to provide financial agents with precise option intrinsic value calculation capabilities. It is implemented purely in Node.js and has no network dependencies. Before use, install `@deepseek-ai/cordis` and `@deepseek-ai/dsh-tools`, and enable the plugin via the command line. After installation, users can directly invoke its tools in a session to perform calculations.