Fix: Remove readonly attribute from parameter name input field

The parameter name field had readonly='readonly' which prevented users from entering values.

This fix allows users to:
- Enter parameter name directly in the form field
- Modify parameter names during editing
- Type any parameter name they need

The readonly attribute was from a mistaken assumption that values would be pre-filled by JavaScript.

🤖 Generated with Claude Code

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

myproject/products/forms.py

@@ -804,8 +804,7 @@ class ConfigurableKitProductAttributeForm(forms.ModelForm):
         widgets = {
             'name': forms.TextInput(attrs={
                 'class': 'form-control param-name-input',
-                'placeholder': 'Например: Длина, Цвет, Размер',
-                'readonly': 'readonly'  # Должен быть заполнен через JavaScript
+                'placeholder': 'Например: Длина, Цвет, Размер'
             }),
             'position': forms.NumberInput(attrs={
                 'class': 'form-control param-position-input',