DeepSeek Harness Progressive Tools Plugin: Progressive Tool Discovery in Stable Agent Mode

`dsh-progressive-tools` is a DeepSeek Harness (DSH) plugin designed to optimize context caching through a stable agent mode. It keeps the full tool catalog in memory and sends only a small, fixed tool surface, ensuring a stable request prefix. By reducing the number of visible tools by 87% and cached-read tokens by 79%, the plugin significantly lowers latency by 54% while supporting safety controls. Although uncached input tokens may increase slightly, it is well suited to DeepSeek Harness scenarios that prioritize performance and stability.