dsh-interval: An Interval Training Plan Generator

`dsh-interval` is a lightweight plugin for DeepSeek Harness (DSH) that generates local interval training plans for running. Implemented in pure Node.js without network dependencies, it supports dynamic training plan generation via parameters. The installation command is `dsh plugin add github:uckkk/dsh-interval`. When using it, make sure the required peerDependencies at specific versions are installed. It is suitable for scenarios that require offline use or quick generation of fixed-format training plans.