fix: delivery-selector price/currency not converting on currency switch

Component read item.currency (source) as both the display label and the
conversion target, so amounts never actually converted - only the label
technically matched. Now converts deliveryPrice/selectedDeliveryTotal via
CurrencyRatesService and labels with the shopper's selected currency.

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

src/app/components/delivery-selector/delivery-selector.component.ts

@@ -1,8 +1,10 @@
-import { ChangeDetectionStrategy, Component, EventEmitter, Input, Output } from '@angular/core';
+import { ChangeDetectionStrategy, Component, EventEmitter, Input, Output, inject } from '@angular/core';
 import { DecimalPipe } from '@angular/common';
 import { FormsModule } from '@angular/forms';
 import { CartItem, DeliveryOption } from '../../models';
 import { TranslatePipe } from '../../i18n/translate.pipe';
+import { LanguageService } from '../../services/language.service';
+import { CurrencyRatesService } from '../../services/currency-rates.service';
 
 let nextDeliverySelectorId = 0;
 
@@ -15,6 +17,9 @@ let nextDeliverySelectorId = 0;
   changeDetection: ChangeDetectionStrategy.OnPush
 })
 export class DeliverySelectorComponent {
+  private readonly languageService = inject(LanguageService);
+  private readonly currencyRates = inject(CurrencyRatesService);
+
   @Input({ required: true }) item: CartItem | null = null;
 
   @Output() selectedDeliveryChange = new EventEmitter<DeliveryOption | null>();
@@ -29,10 +34,20 @@ export class DeliverySelectorComponent {
     return this.item?.selectedDelivery ?? null;
   }
 
-  get currency(): string {
+  /** Source currency the item's prices are stored in. */
+  get sourceCurrency(): string {
     return this.item?.currency || 'RUB';
   }
 
+  /** Currency the shopper has selected for display. */
+  get currency(): string {
+    return this.languageService.currentCurrency();
+  }
+
+  private convert(amount: number): number {
+    return this.currencyRates.convert(amount, this.sourceCurrency, this.currency);
+  }
+
   get required(): boolean {
     return this.item?.deliveryMode !== 'digital'
       && this.options.length > 0
@@ -48,7 +63,8 @@ export class DeliverySelectorComponent {
   }
 
   get selectedDeliveryTotal(): number {
-    return (this.selectedDelivery?.deliveryPrice ?? 0) * (this.item?.quantity ?? 1);
+    const base = (this.selectedDelivery?.deliveryPrice ?? 0) * (this.item?.quantity ?? 1);
+    return this.convert(base);
   }
 
   optionKey(option: DeliveryOption): string {
@@ -57,7 +73,7 @@ export class DeliverySelectorComponent {
 
   optionLabel(option: DeliveryOption): string {
     const details = [option.deliveryPlace, option.deliveryTime].filter(Boolean);
-    details.push(`${option.deliveryPrice.toFixed(2)} ${this.currency}`);
+    details.push(`${this.convert(option.deliveryPrice).toFixed(2)} ${this.currency}`);
     return details.join(' • ');
   }