Introduces Cart and CartItem models, admin, serializers, and API endpoints for shopping cart management for both authenticated and anonymous users. Adds Review model, serializers, and endpoints for product reviews, including public creation and retrieval. Updates ProductImage ordering, enhances order save logic with notification, and improves product and order endpoints with new actions and filters. Includes related migrations for commerce, configuration, social chat, and Deutsche Post integration.
Added Deutsche Post as a shipping carrier, including new models, admin, serializers, and API client integration. Updated Carrier and SiteConfiguration models to support Deutsche Post, including shipping price and API credentials. Added requirements for the Deutsche Post API client and dependencies.
