feat: enhance checkout process with purchase editing and status handling

- Implemented purchase editing functionality in CheckoutPageComponent, allowing users to modify items in their purchase.
- Added a new guard (checkoutPendingPurchaseGuard) to prevent navigation away from the checkout page while a purchase is in progress.
- Updated the login page to handle return URLs after authentication.
- Enhanced product detail page to support direct purchases with a new buyNow method.
- Introduced new UI elements and logic to handle purchase status, including expired and rejected states in PurchaseStatusPageComponent.
- Improved cart component to allow editing of item quantities with a toggle button.
- Added quantity selector enhancements to disable controls when necessary.
- Updated tests to cover new functionalities and ensure proper behavior of components.

src/app/shared/components/cart/cart.component.html

@@ -5,16 +5,30 @@
   <header class="d-flex align-items-center p-3 justify-content-between bg-transparent cart-header">
     <h2 class="m-0 text-uppercase fw-bold cart-title">{{ title() }}</h2>
 
-    @if (showClose()) {
-      <button
-        class="btn btn-link p-0 border-0 d-inline-flex align-items-center justify-content-center cart-close-btn"
-        type="button"
-        aria-label="Cerrar carrito"
-        (click)="closed.emit()"
-      >
-        <i class="fa-solid fa-xmark"></i>
-      </button>
-    }
+    <div class="d-flex align-items-center cart-header-actions">
+      @if (!readonly() && allowEditing() && items().length > 0) {
+        <button
+          class="btn btn-link p-0 border-0 cart-edit-btn"
+          type="button"
+          [attr.aria-pressed]="editing()"
+          [disabled]="editingDisabled()"
+          (click)="toggleEditing()"
+        >
+          {{ editing() ? 'Listo' : 'Modificar' }}
+        </button>
+      }
+
+      @if (showClose()) {
+        <button
+          class="btn btn-link p-0 border-0 d-inline-flex align-items-center justify-content-center cart-close-btn"
+          type="button"
+          aria-label="Cerrar carrito"
+          (click)="closed.emit()"
+        >
+          <i class="fa-solid fa-xmark"></i>
+        </button>
+      }
+    </div>
   </header>
 
   <div class="d-grid w-100 flex-grow-1 overflow-y-auto cart-items-container">
@@ -31,6 +45,9 @@
         [discountPercentage]="item.discountPercentage"
         [attributes]="item.attributes"
         [quantity]="getItemQuantity(item)"
+        [readonly]="readonly()"
+        [quantityDisabled]="editingDisabled() || (allowEditing() && !editing())"
+        [showRemove]="allowRemove()"
         (quantityChange)="onItemQuantityChange(idx, $event)"
         (remove)="onItemRemove(idx)"
       />