fix(checkout): refresh expired carts

src/app/core/layout/store-layout/store-layout.component.spec.ts

@@ -681,10 +681,13 @@ describe('StoreLayoutComponent', () => {
     expect((fixture.componentInstance as any).isCartOpen()).toBe(false);
   });
 
-  it('shows the backend message when starting checkout fails', async () => {
-    const message = 'Alcanzaste el límite de compra para este producto.';
+  it('shows the backend message and refreshes the cart when its reservation expired', async () => {
+    const message = 'La reserva de stock venció. Usá el carrito activo para continuar.';
     checkoutServiceStub.startCheckout.mockRejectedValue(
-      new HttpErrorResponse({ status: 422, error: { message } }),
+      new HttpErrorResponse({
+        status: 422,
+        error: { code: 'stock_reservation.expired', message },
+      }),
     );
     cartState.set({
       id: 1,
@@ -702,11 +705,14 @@ describe('StoreLayoutComponent', () => {
     });
 
     const fixture = TestBed.createComponent(StoreLayoutComponent);
+    const loadCart = vi.spyOn(TestBed.inject(CartService), 'loadCart');
     fixture.detectChanges();
+    loadCart.mockClear();
 
     await (fixture.componentInstance as any).onCheckoutClick();
 
     expect(TestBed.inject(ToastService).danger).toHaveBeenCalledWith(message);
+    expect(loadCart).toHaveBeenCalledOnce();
   });
 
   it('allows modifying quantities directly in the regular cart without a toggle', () => {

src/app/core/layout/store-layout/store-layout.component.ts

@@ -18,7 +18,10 @@ import { ButtonComponent } from '../../../shared/components/button/button.compon
 import { CartItem, CartItemVariantValue } from '../../services/cart/cart.interface';
 import { AuthService } from '../../services/auth/auth.service';
 import { findMenu } from '../../services/menu.utils';
-import { CheckoutService } from '../../services/checkout.service';
+import {
+  CheckoutService,
+  isExpiredStockReservationResponse,
+} from '../../services/checkout.service';
 import { ToastService } from '../../services/toast.service';
 import { Category } from '../../services/tenant.interface';
 
@@ -285,6 +288,11 @@ export class StoreLayoutComponent implements OnInit {
           : 'No se pudo iniciar la compra.';
       this.toastService.danger(message);
 
+      if (error instanceof HttpErrorResponse && isExpiredStockReservationResponse(error.error)) {
+        this.cartService.loadCart().subscribe({
+          error: (refreshError) => console.error('Error refreshing expired cart', refreshError),
+        });
+      }
     } finally {
       this.isCreatingPurchase.set(false);
     }

src/app/core/services/checkout.service.ts

@@ -45,6 +45,21 @@ export function isInsufficientStockResponse(value: unknown): value is Insufficie
   );
 }
 
+export interface ExpiredStockReservationResponse {
+  code: 'stock_reservation.expired';
+  message: string;
+}
+
+export function isExpiredStockReservationResponse(
+  value: unknown,
+): value is ExpiredStockReservationResponse {
+  return (
+    typeof value === 'object' &&
+    value !== null &&
+    (value as Partial<ExpiredStockReservationResponse>).code === 'stock_reservation.expired'
+  );
+}
+
 export type StartCheckoutPayload =
   | {
       cart_id: number;

src/app/features/store/pages/category-items-page/category-items-page.component.ts

@@ -23,7 +23,10 @@ import {
 
 import { AuthService } from '../../../../core/services/auth/auth.service';
 import { CartService } from '../../../../core/services/cart/cart.service';
-import { CheckoutService } from '../../../../core/services/checkout.service';
+import {
+  CheckoutService,
+  isExpiredStockReservationResponse,
+} from '../../../../core/services/checkout.service';
 import {
   CatalogGroupLayout,
   CategoryItemsResponse,
@@ -176,6 +179,11 @@ export class CategoryItemsPageComponent {
           : 'No se pudo iniciar la compra directa.';
       this.toastService.danger(message);
 
+      if (error instanceof HttpErrorResponse && isExpiredStockReservationResponse(error.error)) {
+        this.cartService.loadCart().subscribe({
+          error: (refreshError) => console.error('Error refreshing expired cart', refreshError),
+        });
+      }
     } finally {
       this.creatingDirectPurchase.set(false);
     }

src/app/features/store/pages/search-page/search-page.component.ts

@@ -24,7 +24,10 @@ import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
 
 import { CartService } from '../../../../core/services/cart/cart.service';
 import { AuthService } from '../../../../core/services/auth/auth.service';
-import { CheckoutService } from '../../../../core/services/checkout.service';
+import {
+  CheckoutService,
+  isExpiredStockReservationResponse,
+} from '../../../../core/services/checkout.service';
 import {
   CatalogFeaturedItem,
   CatalogFeaturedItems,
@@ -208,6 +211,11 @@ export class SearchPageComponent {
           : 'No se pudo iniciar la compra directa.';
       this.toastService.danger(message);
 
+      if (error instanceof HttpErrorResponse && isExpiredStockReservationResponse(error.error)) {
+        this.cartService.loadCart().subscribe({
+          error: (refreshError) => console.error('Error refreshing expired cart', refreshError),
+        });
+      }
     } finally {
       this.creatingDirectPurchase.set(false);
     }

src/app/features/store/pages/store-home-page/store-home-page.component.ts

@@ -21,6 +21,7 @@ import { TenantService } from '../../../../core/services/tenant.service';
 import { ToastService } from '../../../../core/services/toast.service';
 import {
   CheckoutService,
+  isExpiredStockReservationResponse,
   isInsufficientStockResponse,
 } from '../../../../core/services/checkout.service';
 import {
@@ -221,6 +222,14 @@ export class StoreHomePageComponent implements OnInit, OnDestroy {
     } catch (error) {
       console.error('Failed to create direct purchase:', error);
 
+      if (error instanceof HttpErrorResponse && isExpiredStockReservationResponse(error.error)) {
+        this.toastService.danger(error.error.message);
+        this.cartService.loadCart().subscribe({
+          error: (refreshError) => console.error('Error refreshing expired cart', refreshError),
+        });
+        return;
+      }
+
       if (error instanceof HttpErrorResponse && isInsufficientStockResponse(error.error)) {
         const unavailableIds = error.error.unavailable_items
           .map((item) => item.variant_id)