dsh-voltage-drop: Voltage Drop Verification

DeepSeek Harness (DSH) launched the `dsh-voltage-drop` plugin, designed to provide agents with localized voltage drop verification capabilities. Implemented purely in Node.js and without any dependency on network requests, the plugin ensures efficient and stable calculations. Users need to install the dependency libraries `@deepseek-ai/cordis` and `@deepseek-ai/dsh-tools`, then install the plugin using the `dsh plugin add` command. Once loaded, developers can directly invoke the `voltage_drop` tool during a conversation to perform precise calculations. The plugin is especially suitable for offline or intranet environments and strengthens the electrical calculation capabilities of the DSH ecosystem.