* FIX: Redsys redirection token payments (C and R) now send complete EMV3DS browser data (accept header, JavaScript enabled, etc.) to avoid SIS0573/SIS0653 authentication rejects, and force `DS_MERCHANT_DIRECTPAYMENT` to true for COF flows.
* FIX: Improved token payment debug logs to include saved meta and order status when finishing the flow, making troubleshooting clearer.

* UPDATE: Migrated InSite payment flow from SOAP to REST using the unified Redsys REST client, keeping token/COF handling, preauthorizations, and step-by-step debug logs intact for Apple/Google Pay and subscriptions reuse.
* NEW: Added terminal type selection (Mixed/Secure) for Apple Pay and Google Pay to choose the proper flow (direct vs. secure redirect).
* FIX: Prevented PHP 8.1+ deprecation notices in the onboarding/setup page by validating the menu slug before calling add_submenu_page().

* Tweak – Explain that plain text emails don’t track opens.

* Fix – Ensure referral coupons are validated properly when using WooCommerce block-based checkout pages.
* Fix – Prevent existing customers with one previous order from incorrectly receiving a second referral.