feat: Add SKU field to ProductKit form for kit creation

- Added 'sku' field to ProductKitForm meta fields list
- Added SKU label in form labels
- Added SKU widget styling in __init__ method with helpful placeholder
- Updated productkit_form.html template to display SKU field after name, before description
- Updated form field filtering to exclude 'sku' from dynamic loop to prevent duplication

🤖 Generated with Claude Code

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

myproject/products/forms.py

@@ -82,11 +82,12 @@ class ProductKitForm(forms.ModelForm):
     class Meta:
         model = ProductKit
         fields = [
-            'name', 'description', 'categories',
+            'name', 'sku', 'description', 'categories',
             'tags', 'pricing_method', 'fixed_price', 'markup_percent', 'markup_amount', 'is_active'
         ]
         labels = {
             'name': 'Название',
+            'sku': 'Артикул',
             'description': 'Описание',
             'categories': 'Категории',
             'tags': 'Теги',
@@ -104,6 +105,10 @@ class ProductKitForm(forms.ModelForm):
             'class': 'form-control',
             'placeholder': 'Введите название комплекта'
         })
+        self.fields['sku'].widget.attrs.update({
+            'class': 'form-control',
+            'placeholder': 'Артикул (необязательно, будет сгенерирован автоматически)'
+        })
         self.fields['description'].widget.attrs.update({
             'class': 'form-control',
             'rows': 3