Add POI feature and imporve the overall backend implementation

services/inventory/app/repositories/ingredient_repository.py

@@ -332,7 +332,10 @@ class IngredientRepository(BaseRepository[Ingredient, IngredientCreate, Ingredie
                     'ingredient': ingredient,
                     'current_stock': float(current_stock) if current_stock else 0.0,
                     'threshold': ingredient.low_stock_threshold,
-                    'needs_reorder': current_stock <= ingredient.reorder_point if current_stock else True
+                    'needs_reorder': (
+                        current_stock <= ingredient.reorder_point
+                        if current_stock and ingredient.reorder_point is not None else True
+                    )
                 })
             
             return results

services/inventory/app/repositories/stock_repository.py

@@ -98,6 +98,28 @@ class StockRepository(BaseRepository[Stock, StockCreate, StockUpdate], BatchCoun
             logger.error("Failed to get stock by ingredient", error=str(e), ingredient_id=ingredient_id)
             raise
 
+    async def get_stock_by_product(
+        self,
+        tenant_id: UUID,
+        inventory_product_id: UUID,
+        include_unavailable: bool = False
+    ) -> List[Stock]:
+        """
+        Get all stock entries for a specific product.
+
+        Note: inventory_product_id and ingredient_id refer to the same entity.
+        The 'ingredients' table is used as a unified catalog for both raw ingredients
+        and finished products, distinguished by the product_type field.
+
+        This method is an alias for get_stock_by_ingredient for clarity when called
+        from contexts that use 'product' terminology (e.g., procurement service).
+        """
+        return await self.get_stock_by_ingredient(
+            tenant_id=tenant_id,
+            ingredient_id=inventory_product_id,
+            include_unavailable=include_unavailable
+        )
+
     async def get_total_stock_by_ingredient(self, tenant_id: UUID, ingredient_id: UUID) -> Dict[str, float]:
         """Get total stock quantities for an ingredient"""
         try: