Enhance product handling and seeding logic

- Added a call to sync properties JSON in UpdateProductRelations job if the method exists.
- Updated ProductFieldsForDetail to provide a default value of '-' for missing property values.
- Simplified the insertion logic in ProductPropertyValuesSeeder by replacing 'tm' with 'tk' in the value field and removed commented-out code for clarity.

app/Nova/Resources/Ecommerce/Product/Product/Concerns/ProductFieldsForDetail.php

@@ -134,8 +134,8 @@ class ProductFieldsForDetail
                             'name' => $property->attribute->slug,
                             'type' => $property->attribute->type,
                             'default' => $property->attribute->type === 'select'
-                                            ? $property->values->first()->value?->id
-                                            : $property->values->first()->product_custom_value,
+                                            ? $property->values->first()->value?->id ?? '-'
+                                            : $property->values->first()->product_custom_value ?? '-',
                             'options' => $property->attribute->values->map(fn ($value) => [
                                 'label' => $value->value,
                                 'value' => $value->id,