phase-7: add reusable input-output widget library and default registry

src/app/widgets/ui/footer-navigation-widget.component.ts

@@ -0,0 +1,44 @@
+import { CommonModule } from '@angular/common';
+import { ChangeDetectionStrategy, Component, EventEmitter, Input, Output } from '@angular/core';
+
+export interface FooterNavigationLink {
+  id: string;
+  label: string;
+  href: string;
+}
+
+@Component({
+  selector: 'app-footer-navigation-widget',
+  standalone: true,
+  imports: [CommonModule],
+  template: `
+    <footer class="footer-nav-widget">
+      <nav>
+        <ul>
+          @for (link of links; track link.id) {
+            <li>
+              <button type="button" (click)="onLinkClick(link)">{{ link.label }}</button>
+            </li>
+          }
+        </ul>
+      </nav>
+    </footer>
+  `,
+  styles: [
+    `
+      .footer-nav-widget { padding: 1rem; border-top: 1px solid var(--border-color, #d3dad9); }
+      ul { display: flex; gap: 1rem; list-style: none; margin: 0; padding: 0; flex-wrap: wrap; }
+      button { background: transparent; border: none; color: var(--text-secondary, #667a77); cursor: pointer; }
+    `
+  ],
+  changeDetection: ChangeDetectionStrategy.OnPush
+})
+export class FooterNavigationWidgetComponent {
+  @Input() links: FooterNavigationLink[] = [];
+
+  @Output() linkSelected = new EventEmitter<FooterNavigationLink>();
+
+  onLinkClick(link: FooterNavigationLink): void {
+    this.linkSelected.emit(link);
+  }
+}