DeepSeek Harness API Key Rotation Pool Plugin

`dsh-api-key-pool` is a security plugin for DeepSeek Harness (DSH) designed to resolve rate-limiting issues in multi-API-key scenarios. Its core features include automatic multi-key rotation, automatic failover, exponential-backoff cooldown, Web panel management, and REST API control. Installation requires copying the files into the plugin directory and configuring `package.json`. It supports static YAML configuration as well as dynamic Web/REST management, and depends on Node.js 18 and related DSH modules.