feat: complete newspaperui component library with docs site

- 18 React components (Layout/Section/Article/Layer/Masthead/Rule +
  Headline/Subhead/Kicker/BodyText/Quote/Byline/Dateline/Caption +
  Image/Figure/Video/PullQuote)
- Theme: warm off-white palette, Source Serif 4 / Cormorant Garamond /
  Inter / Noto Serif SC/JP, visual weight mapping, dark mode
- Docs: Landing page, 6 Blocks (zh/en/jp), component API docs
- GitHub Pages deployment via static export

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

packages/components/src/Text/Caption.tsx

@@ -10,6 +10,18 @@ export interface CaptionProps {
   children: ReactNode;
 }
 
+/**
+ * Caption — 图片说明（italic + credit small-caps）
+ *
+ * - 主体文字为 italic 衬线，描述图片内容
+ * - credit 部分以 small-caps 显示摄影师/来源信息
+ * - 渲染为 figcaption，语义化配合 Figure 使用
+ *
+ * @example
+ * <Caption credit="Photograph by Jane Doe">
+ *   A view of the city skyline at sunset.
+ * </Caption>
+ */
 export const Caption: React.FC<CaptionProps> = ({ credit, className, style, children }) => {
   const config = visualWeights.Caption.Standard!;
   return (