refactor: extract shared app-breadcrumb component (Z14)

Only breadcrumb logic anywhere in the storefront was a local signal +
inline markup inside catalog-container. Extracted a generic
shared/ui/breadcrumb component (rootLabel/items/ariaLabel inputs,
rootClick/itemClick outputs) and repointed catalog-container onto it,
removing the now-dead inline SCSS block. Future breadcrumb usages
(product detail, admin) have something to reuse instead of duplicating.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/shared/ui/breadcrumb/breadcrumb.component.html

@@ -0,0 +1,7 @@
+<nav class="app-breadcrumb" [attr.aria-label]="ariaLabel() || null">
+  <button type="button" (click)="rootClick.emit()">{{ rootLabel() }}</button>
+  @for (item of items(); track item.id) {
+    <span aria-hidden="true">/</span>
+    <button type="button" (click)="itemClick.emit(item)">{{ item.label }}</button>
+  }
+</nav>

src/app/shared/ui/breadcrumb/breadcrumb.component.scss

@@ -0,0 +1,19 @@
+.app-breadcrumb {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  flex-wrap: wrap;
+  color: var(--text-secondary);
+  font-size: var(--font-size-md, 0.9375rem);
+
+  button {
+    border: 0;
+    padding: 0;
+    background: transparent;
+    color: var(--primary-color);
+    font: inherit;
+    font-weight: var(--font-weight-bold, 700);
+    text-decoration: none;
+    cursor: pointer;
+  }
+}

src/app/shared/ui/breadcrumb/breadcrumb.component.ts

@@ -0,0 +1,26 @@
+import { ChangeDetectionStrategy, Component, input, output } from '@angular/core';
+
+export interface BreadcrumbItem {
+  id: string | number;
+  label: string;
+}
+
+/**
+ * Generic breadcrumb trail. Consumer owns navigation - this component only
+ * renders the trail and emits which item was clicked (root or a trail item).
+ */
+@Component({
+  selector: 'app-breadcrumb',
+  standalone: true,
+  templateUrl: './breadcrumb.component.html',
+  styleUrl: './breadcrumb.component.scss',
+  changeDetection: ChangeDetectionStrategy.OnPush,
+})
+export class BreadcrumbComponent {
+  readonly rootLabel = input.required<string>();
+  readonly items = input<BreadcrumbItem[]>([]);
+  readonly ariaLabel = input<string>('');
+
+  readonly rootClick = output<void>();
+  readonly itemClick = output<BreadcrumbItem>();
+}