Move <app-footer> to the root app component

The <app-footer> component is now included only in app.component.html to avoid duplication across pages. This simplifies maintenance and ensures consistent behavior throughout the application.

frontend/src/app/rules/rules.component.html

@@ -260,5 +260,4 @@
       <p style="display: none;">Scroll Down</p>
     </a>
   </main>
-  <app-footer></app-footer>
 </ng-container>