docs: 渐进式插件教程（L0→L5）+ DESIGN.md 视觉规范 + plugin-template 脚手架

packages/plugin-template/shims/react.js

@@ -0,0 +1,16 @@
+// 构建期别名目标：react → 宿主全局单例（双 React 实例会导致 hooks 失效）
+const R = window.__ASO_PLUGIN_HOST__.react
+export default R
+export const {
+  useState,
+  useEffect,
+  useRef,
+  useMemo,
+  useCallback,
+  createContext,
+  useContext,
+  Fragment,
+  memo,
+  forwardRef,
+  createElement
+} = R