feat(0): add createBreadcrumbs composable

[johnleider]

Summary

Lightweight breadcrumb navigation composable following the same patterns as createPagination.

Features

• Path manipulation: push, pop, select, replace
• Navigation: first(), prev() for going back
• Automatic collapse: Long paths collapse middle items with ellipsis
• v-model support: Pass a shallowRef for two-way binding
• Trinity pattern: createBreadcrumbsContext for dependency injection

API

const breadcrumbs = createBreadcrumbs({
  path: [{ id: 'home', text: 'Home' }],
  visible: 4,
  ellipsis: '…',
})

breadcrumbs.push({ text: 'Products' })
breadcrumbs.items.value
// → [{ type: 'crumb', ... }, { type: 'ellipsis', ... }, { type: 'crumb', ... }]

Includes

• Composable implementation
• Documentation page
• 37 tests (all passing)

[pkg-pr-new]

Open in StackBlitz

commit: ea79297