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>

.gitignore

@@ -43,3 +43,7 @@ coverage
 # Misc
 .cache
 .temp
+
+# IDE / tools
+.playwright-mcp/
+screenshots/