dsh-percentile: DeepSeek Harness Percentile Plugin

`dsh-percentile` is a plugin for DeepSeek Harness that locally computes percentiles for inference metrics, addressing the limitation that averages cannot fully reveal details of data distribution. Maintained by developer `uckkk`, it is implemented in pure Node.js, has no network dependencies, and offers high execution efficiency. Installation requires `@deepseek-ai/cordis` ^4.0.1 and `@deepseek-ai/dsh-tools` >= 0.1.0-rc.6. It is suitable for developers and operations personnel who need in-depth analysis of distributions for metrics such as latency and token count, ensuring stable performance in offline environments.