WooComércio Royal Mail / Método de Entrega Royal Mail para WooCommerce 4.0.0

* Add - Royal Mail and Parcelforce rates effective April 7, 2026.
* Add - Manual "Sync rates from local files" button in WooCommerce → Settings → Shipping → Royal Mail.
* Tweak - Migrate rate data from hardcoded PHP arrays to local JSON files; rates are cached in the database and re-synced automatically on plugin update.

* Add - International Tracked Heavier (Medium Parcel) rates for January 2026 online pricing.

* Tweak - WooCommerce 10.6 Compatibility.

* Fix - International Tracked & Signed now supports MEDIUM_PARCEL up to 20kg for custom boxes.
* Tweak - WooCommerce 10.5 Compatibility.

* Tweak - WordPress 6.9 and WooCommerce 10.4 Compatibility.

* Tweak - WooCommerce 10.3 Compatibility.

* Add - October 2025 regular and online pricing changes.

* Update - Parcelforce & International Tracked rates.
* Tweak - WooCommerce 10.2 Compatibility.

* Tweak - WooCommerce 10.1 Compatibility.

* Tweak - WooCommerce 10.0 Compatibility.