fix: align frontend InventoryItem type with actual API response
InventoryItemResponse returns flat fields (product_name, barcode, category)
not a nested product object. Frontend interface and templates were using
item.product.name / item.product.brand which threw TypeError on render,
blanking the inventory tab.
- InventoryItem: remove product:Product, add product_name/barcode/category
- InventoryStats: fix total_products→available_items, expired→expired_items,
items_by_location→locations
- item IDs are int not string — update deleteItem/updateItem/consumeItem sigs
- EditItemModal, RecipesView, InventoryList: fix all item.product.xxx refs
pyr0ball
828efede42