fix(icons): icon-only button accessibility pass

Swept every icon-only button app-wide for an accessible name. Found
three relying on title-only (not reliably announced by screen
readers) or nothing at all: region-selector's detect-location button,
the carousel add-to-cart button, and the subcategories add-to-cart
button (had no label at all). All now have aria-label.

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

src/app/pages/category/subcategories.component.html

@@ -78,7 +78,7 @@
                     <span class="current-price">{{ item.price }} {{ item.currency }}</span>
                   }
                 </div>
-                <button class="item-cart-btn" (click)="addToCart(item.itemID, $event)">
+                <button class="item-cart-btn" (click)="addToCart(item.itemID, $event)" [attr.aria-label]="'carousel.addToCart' | translate">
                   <app-icon name="cart" [size]="16" />
                 </button>
               </div>