nature-paper-workflow

论文生产链顶层路由 skill：识别阶段并路由到子 skill。Use when user says 论文生产链、paper workflow、帮我写论文、帮我投稿、经济学论文、DiD、IV、AER、QJE. This skill does NOT execute paper tasks; it routes to sub-skills. 行为范围：只读子 skill SKILL.md，无网络/subprocess/写入。