dsh-nth-prime: Nth Prime Calculator Plugin

The `dsh-nth-prime` plugin for DeepSeek Harness (DSH) is maintained by uckkk and focuses on providing prime number computation capabilities to DSH. It is implemented locally in pure Node.js, allowing direct retrieval of the prime number at a specified index without any network requests. To install it, run `dsh plugin add github:uckkk/dsh-nth-prime`. Because the plugin runs with the current process permissions, it is recommended to review its source code and license before use. This is a lightweight, network-independent mathematical utility solution.