Fixed 'items' is not defined error in demo seed script:
- Changed 'items' references to 'items_data' (the function parameter)
- Updated product_names extraction to use dict.get() for safety
- Fixed create_po_reasoning_supplier_contract call to use correct parameters
(contract_quantity instead of trust_score)
This resolves the warnings about failed reasoning_data generation
during purchase order seeding.
e67a83ceb0