feat: full FrontOffice updates - discount store, blog, payment gateway, UI improvements

- Discount store pages (products, cart, orders, order detail)
- Blog pages and services
- Payment gateway callback page
- AppImage component, EmptyState, LoadingState, PageHeader
- DiscountCartService, DiscountOrderService, DiscountProductService
- BlogCategoryService, BlogPostService, SitePageService, ImageCacheService
- PhoneVerifyForm component
- Profile Hub page
- UI/UX improvements across all pages
- landing.js for homepage
- Config and routing updates

src/FrontOffice.Main/Pages/Gateway/CartChooser.razor.cs

@@ -0,0 +1,47 @@
+using Microsoft.AspNetCore.Components;
+using Microsoft.JSInterop;
+using FrontOffice.Main.Utilities;
+
+namespace FrontOffice.Main.Pages.Gateway;
+
+public partial class CartChooser : IDisposable
+{
+    [Inject] private CartService CartService { get; set; } = default!;
+    [Inject] private DiscountCartService DiscountCartService { get; set; } = default!;
+    [Inject] private IJSRuntime JS { get; set; } = default!;
+
+    private int _cartCount;
+    private int _discountCartCount;
+
+    protected override async Task OnInitializedAsync()
+    {
+        await CartService.EnsureInitializedAsync();
+        await DiscountCartService.EnsureInitializedAsync();
+
+        _cartCount = CartService.Count;
+        _discountCartCount = DiscountCartService.Count;
+
+        CartService.OnChange += OnCartChanged;
+        DiscountCartService.OnChange += OnDiscountCartChanged;
+    }
+
+    private void OnCartChanged()
+    {
+        _cartCount = CartService.Count;
+        InvokeAsync(StateHasChanged);
+    }
+
+    private void OnDiscountCartChanged()
+    {
+        _discountCartCount = DiscountCartService.Count;
+        InvokeAsync(StateHasChanged);
+    }
+
+    public void Dispose()
+    {
+        CartService.OnChange -= OnCartChanged;
+        DiscountCartService.OnChange -= OnDiscountCartChanged;
+    }
+
+    private async Task GoBack() => await JS.InvokeVoidAsync("history.back");
+}