DSH Plugin: dsh-design-audit

`dsh-design-audit` is the first tool in the DeepSeek Harness plugin ecosystem to fill the gap in the design review and optimization loop. It separates measurement from judgment, uses headless Chrome to collect objective evidence, and generates prioritized issue lists based on deterministic rules such as WCAG 2.2. The plugin covers accessibility, typography, layout, motion, and occlusion detection, provides paste-ready CSS fix suggestions, and supports validating fixes through retest deltas. It has zero npm dependencies, requires Node ≥ 22, makes no aesthetic judgments, and is designed to help developers efficiently identify and resolve design defects.