feat: enhance product detail loading and initialization logic

- Introduced an `_initialized` flag to manage product loading state more effectively.
- Updated `OnParametersSetAsync` to conditionally load product details based on the initialization state and valid product ID.
- Refactored product retrieval logic in `ProductService` to handle invalid IDs and improve fallback mechanisms for fetching product details.

These changes improve the reliability and performance of the product detail component, ensuring that product information is loaded correctly and efficiently.

src/FrontOffice.Main/Pages/Store/ProductDetail.razor.cs

@@ -21,6 +21,7 @@ public partial class ProductDetail : ComponentBase, IDisposable
 
     private Product? _product;
     private bool _loading;
+    private bool _initialized;
     private int _qty = 1;
     private const int MinQty = 1;
     
@@ -48,29 +49,35 @@ public partial class ProductDetail : ComponentBase, IDisposable
     private bool IsInCart => CurrentCartItem is not null;
     private int CurrentCartQuantity => CurrentCartItem?.Quantity ?? 0;
 
-    protected override async Task OnParametersSetAsync()
-    {
-      
-    }
-
     protected override async Task OnInitializedAsync()
     {
         _isAuthenticated = await AuthService.IsAuthenticatedAsync();
         await Cart.EnsureInitializedAsync();
         Cart.OnChange += HandleCartChanged;
-        
-   
-        
+        _initialized = true;
+    }
+
+    protected override async Task OnParametersSetAsync()
+    {
+        if (!_initialized || id <= 0)
+            return;
+
+        await LoadProductAsync();
+    }
+
+    private async Task LoadProductAsync()
+    {
         _loading = true;
         _product = await ProductService.GetByIdAsync(id);
         _loading = false;
+
         if (_product is not null)
         {
             _galleryItems = BuildGalleryItems(_product);
             _selectedGalleryImage = _galleryItems.FirstOrDefault();
             _categoryPaths = _product.Categories;
             UpdateBreadcrumb();
-            _qty = Math.Clamp(CurrentCartItem?.Quantity ?? _qty, MinQty, MaxQty);
+            _qty = Math.Clamp(CurrentCartItem?.Quantity ?? MinQty, MinQty, Math.Max(MinQty, MaxQty));
         }
         else
         {
@@ -78,19 +85,16 @@ public partial class ProductDetail : ComponentBase, IDisposable
             _categoryPaths = Array.Empty<ProductCategoryPathInfo>();
             _breadcrumbItems.Clear();
         }
-
-        StateHasChanged();
-        await base.OnInitializedAsync();
     }
 
     protected override async Task OnAfterRenderAsync(bool firstRender)
     {
-       await base.OnAfterRenderAsync(firstRender);
         if (firstRender)
         {
-            // بارگذاری نرخ VAT
             await VAT.LoadAsync();
         }
+
+        await base.OnAfterRenderAsync(firstRender);
     }
 
     private async Task AddToCart()