refactor: 移除样例页（tutorial design-examples / design-lab shelf）——组件页已含 RouteLine 演示，样例使命完成；导航/目录/视觉基线/散落契约同步清理，25/25 绿（Scatter 组件保留在包中）

apps/design-lab/e2e/visual.spec.ts

@@ -9,7 +9,6 @@ const CASES: [name: string, path: string][] = [
   ['colors', '/colors.html'],
   ['symbols', '/symbols.html'],
   ['components', '/components.html'],
-  ['shelf', '/shelf.html'],
 ]
 
 for (const [name, path] of CASES) {