* Feature - WooCommerce Blocks: Checkout Custom Fields (text, select, checkbox, radio-as-select) now appear on Blocks checkout. Fields with visibility conditions (product/category/cart-amount) are excluded from Blocks and remain classic-only.
* Feature - WooCommerce Blocks: Checkout Fees module now applies simple fees (fixed and percentage) on Blocks checkout via Store API. Checkout-field-conditional fees remain classic-only.
* Enhancement - HPOS: Checkout Files Upload uses consolidated HPOS helper methods for order meta access in email attachments, order display, and file-to-order paths. Store API hook added for Blocks-placed orders.
* Enhancement - Performance: Request-scope caching for checkout fee configuration reduces repeated option lookups during cart calculation.
* Enhancement - Performance: Cart product and category ID caching in checkout custom fields visibility checks reduces redundant cart iteration on classic checkout.
* Fix - PHP 8.2: Resolved uksort deprecation in checkout fees priority sorting.
* Security - Hardening: Strengthened Sales Notifications AJAX validation and access control.
* WooCommerce 10.6.2 Tested
* WordPress 6.9.4 Tested
