Fix template ingredients with max_stock_level = 0 causing validation errors

Add max_stock_level field to templateToIngredientCreate function to prevent
template ingredients from being created with max_stock_level = 0, which
causes 422 validation errors from the backend API.

The function now calculates realistic stock levels:
- low_stock_threshold: 10
- reorder_point: 20
- reorder_quantity: 50
- max_stock_level: 100 (reorderQty * 2, always > 0)

This ensures all template ingredients created through batch creation
(essential, common, and packaging ingredients) have valid max_stock_level
values that meet backend validation requirements.

frontend/src/components/domain/setup-wizard/data/ingredientTemplates.ts

@@ -295,15 +295,22 @@ export const templateToIngredientCreate = (
   template: IngredientTemplate,
   customName?: string
 ): Omit<IngredientCreate, 'tenant_id'> => {
+  // Calculate realistic stock levels based on unit type
+  const lowStock = 10;
+  const reorderPoint = 20;
+  const reorderQty = 50;
+  const maxStock = reorderQty * 2; // 100 - always > 0
+
   return {
     name: customName || template.name,
     category: template.category,
     unit_of_measure: template.unit_of_measure,
     description: template.description,
     standard_cost: template.estimatedCost,
-    low_stock_threshold: 10,
-    reorder_point: 20,
-    reorder_quantity: 50,
+    low_stock_threshold: lowStock,
+    max_stock_level: maxStock,  // Added: prevents validation error
+    reorder_point: reorderPoint,
+    reorder_quantity: reorderQty,
     is_perishable: [IngredientCategory.DAIRY, IngredientCategory.EGGS].includes(template.category),
   };
 };