dsh-worktree-studio: DeepSeek Harness Manual Git Worktree Task Board

`dsh-worktree-studio` is a manual Git worktree task board plugin for DeepSeek Harness. It maps Git branches, worktrees, and DSH sessions one-to-one, supporting the creation of isolated environments, native session integration, state validation, and merge previews. Designed to be non-invasive and without consuming model tokens, it aims to enable isolated verification and safe merging of code changes locally through Git worktrees and a state token mechanism.