What is dd?
Document-Driven Development (文档驱动开发). Use when: (1) /dd help — explain workflow and suggest next step based on project state, (2) /dd init — initialize doc-driven structure in a project, (3) /dd spec [requirement] — create temporary spec to align intent before development, (4) /dd dev [spec-path|doc-path] — implement code following spec or doc (auto enters plan mode for spec-based dev), (5) /dd sync [--check|--scope] — update living docs, archive spec, and audit consistency. Triggers on mentions of: document-driven, design document, doc-driven, spec-driven, 文档驱动, 设计文档, 规格, /dd. Source: zkywalker/doc-driven.