Filter POS showcase kits by showcase__isnull=False

Fix issue where temporary kits created for orders (with order field set
but showcase=NULL) were appearing in POS terminal showcase list.

Problem:
- When creating temporary kit from order edit page, it has order=<Order>
  and showcase=NULL
- get_showcase_kits_for_pos() was showing ALL temporary kits with
  reserved components, regardless of showcase field
- This caused order kits to appear in POS showcase view
- Users couldn't add them to cart (showcase=NULL check failed)

Solution:
- Add showcase__isnull=False filter to ProductKit query
- This ensures only kits explicitly assigned to showcases are shown
- Order kits (showcase=NULL) are now excluded from POS showcase list

Clear separation:
- Temporary kits for orders: order != NULL, showcase = NULL
- Temporary kits for showcases: showcase != NULL

File: pos/views.py:85

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

myproject/pos/views.py

@@ -77,9 +77,12 @@ def get_showcase_kits_for_pos():
     )
     
     # Находим комплекты с резервированными компонентами
+    # ВАЖНО: фильтруем только комплекты, явно привязанные к витрине (showcase__isnull=False)
+    # Это исключает временные комплекты, созданные для заказов (order__isnull=False, showcase=NULL)
     kits_with_showcase_items = ProductKit.objects.filter(
         is_temporary=True,
         status='active',
+        showcase__isnull=False,  # Только витринные комплекты
         kit_items__product_id__in=reserved_products
     ).prefetch_related(
         first_photo_prefetch,