dsh-goal-scaffold: DeepSeek Harness Long-Task Planning and Goal Scaffolding Plugin

`dsh-goal-scaffold` is a DeepSeek Harness (DSH) plugin designed to address the lack of planning in long-task processing. It acts as a gate that intercepts large one-shot requests and prompts users through an interactive window to plan first. Its core features include automatically generating a `plan.md` with acceptance criteria and creating goals with defined caps, while the agent checks off progress item by item during execution. The plugin supports configurable trigger length, session limits, headless-mode compatibility, and application only to human messages, ensuring structured execution and traceability for complex tasks.