Restructure layout components architecture

- Move layout components from layouts/ directory to components/layout/
- Reorganize divider component from data-display to layout category
- Add comprehensive layout component collection including aspect-ratio, bento-grid, box, breakpoint-container, center, column, dashboard-shell, feed-layout, flex, grid-container, hstack, list-detail-layout, scroll-container, section, sidebar-layout, stack, supporting-pane-layout, tabs-container, and vstack
- Update all demo components to match new layout structure
- Refactor routing and index exports to reflect reorganized component architecture

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

projects/demo-ui-essentials/src/app/demos/divider-demo/divider-demo.component.ts

@@ -1,6 +1,6 @@
 import { Component } from '@angular/core';
 import { CommonModule } from '@angular/common';
-import { DividerComponent } from '../../../../../ui-essentials/src/public-api';
+import { DividerComponent } from '../../../../../ui-essentials/src/lib/components/layout';
 
 @Component({
   selector: 'ui-divider-demo',