refactor: update module imports to use module locations

Update all module files to import from canonical module locations
instead of legacy re-export files:
- checkout, orders, customers routes: use module schemas
- catalog, marketplace schemas: use inventory module schemas
- marketplace, customers, inventory, analytics services: use module models

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/modules/inventory/services/inventory_transaction_service.py

@@ -14,7 +14,7 @@ from sqlalchemy.orm import Session
 from app.exceptions import OrderNotFoundException, ProductNotFoundException
 from app.modules.inventory.models.inventory import Inventory
 from app.modules.inventory.models.inventory_transaction import InventoryTransaction
-from models.database.order import Order
+from app.modules.orders.models import Order
 from models.database.product import Product
 
 logger = logging.getLogger(__name__)