Design cart and pricing engine classes

Design the core classes and interfaces for a cart & pricing engine for a food delivery marketplace (e.g., Uber Eats).

The final checkout price is not simply the sum of menu items. It is dynamically computed based on:

• Item customizations : add/remove ingredients, size upgrades, dietary substitutions. Each customization may add $0 or an extra cost.
• Marketplace dynamics : e.g., surge pricing as a multiplier applied to a subtotal (e.g., 1.2×).
• Promotions : coupon codes such as $5 off , 10% off , Buy 1 Get 1 Free (BOGO) , and possibly tiered delivery fees.
• Membership benefits : e.g., subscribers get 0 delivery fee and 5% off eligible items .

Requirements:

1. Cart operations : add/remove items and quantities; apply item-level customizations.
2. Flexible pricing strategies : support multiple independent pricing rules (surge, membership discount, coupons, BOGO, delivery fee rules). Rules should be composable and easy to extend.
3. Receipt breakdown : return an itemized checkout receipt showing at least: base price, add-ons, fees, discounts, and final total.

Provide an object-oriented design: key classes, interfaces, and how they collaborate. Clarify how pricing rules are ordered/combined and how the receipt is produced.