Contextual pricing and publishing APIs use backup region fallback

We're changing the fallback behavior when determining the pricing and publishing that applies to a customer in a specific context. Currently, if a country that doesn't belong to a market is passed as a buyer signal, we use the store defaults. For example, the currency used for pricing will be the store's default currency. With this change, the market for the backupRegion will now be used so currency, catalogs, and other settings from that market will be used when determining pricing and publishing. This fallback matches the behavior on the storefont and allows for consistency in pricing and publishing APIs.

As of API version 2025-07, the following fields will usebackupRegion as a fallback:

• Product.contextualPricing
• ProductVariant.contextualPricing
• Product.publishedInContext

Previous versions will continue to fallback to store defaults.