建议：将 skill 运行时文件收缩到 skills/ 子目录，将营销素材移出 skill 树

**TL;DR (EN):** This repo's `SKILL.md` lives at the repo root, so tools that vend the skill (skills.sh / Skills CLI) pull the **entire repository** — including ~31 MB of marketing images that `SKILL.md` never references. Proposal: put the runtime skill under `skills/nuwa/` and move marketing assets to GitHub Releases (or a folder outside the skill tree), the way `huashu-design` already does for its README GIFs.