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/DiscountStore/Cart.razor.cs

@@ -0,0 +1,56 @@
+using Microsoft.AspNetCore.Components;
+using FrontOffice.Main.Utilities;
+
+namespace FrontOffice.Main.Pages.DiscountStore;
+
+public partial class Cart : IDisposable
+{
+    [Inject] private DiscountCartService DiscountCart { get; set; } = default!;
+
+    protected override async Task OnInitializedAsync()
+    {
+        await DiscountCart.EnsureInitializedAsync();
+        DiscountCart.OnChange += StateHasChanged;
+    }
+
+    private async Task IncrementQty(long productId)
+    {
+        var item = DiscountCart.Items.FirstOrDefault(i => i.ProductId == productId);
+        if (item is null) return;
+        await DiscountCart.UpdateQuantityAsync(productId, item.Quantity + 1);
+    }
+
+    private async Task DecrementQty(long productId)
+    {
+        var item = DiscountCart.Items.FirstOrDefault(i => i.ProductId == productId);
+        if (item is null) return;
+        if (item.Quantity <= 1)
+        {
+            await DiscountCart.RemoveAsync(productId);
+        }
+        else
+        {
+            await DiscountCart.UpdateQuantityAsync(productId, item.Quantity - 1);
+        }
+    }
+
+    private async Task Remove(long productId)
+    {
+        await DiscountCart.RemoveAsync(productId);
+    }
+
+    private void ProceedCheckout()
+    {
+        Navigation.NavigateTo(RouteConstants.DiscountStore.Checkout);
+    }
+
+    private static string FormatPrice(long price) => $"{price:N0} ";
+
+    private static string GetImageUrl(string? imageUrl)
+        => string.IsNullOrWhiteSpace(imageUrl) ? "/images/product-placeholder.svg" : imageUrl.TrimStart('/');
+
+    public void Dispose()
+    {
+        DiscountCart.OnChange -= StateHasChanged;
+    }
+}