Fix: Move carrier live-pricing choice onto ShippingMethod.charge_by

Reverts the earlier per-rate pricing_mode column in favor of extending Lunar's existing charge_by field (cart_total/weight) with a third "live" option, gated by a SupportsLivePricing capability check on the driver. Adds a shared ResolvesFixedPricing trait so any carrier driver can fall back to Lunar's normal price-break resolution, matching the vendor ShipBy driver's own charge_by handling instead of introducing a separate mechanism. Also fixes an incorrect Get() path in the admin form that silently hid the new "live" option.

src/Shipping/Carriers/Acs/AcsRateDriver.php

@@ -4,15 +4,17 @@ namespace Modules\Core\Shipping\Carriers\Acs;
 
 use Lunar\DataTypes\Price;
 use Lunar\DataTypes\ShippingOption;
-use Lunar\Facades\Pricing;
 use Lunar\Shipping\DataTransferObjects\ShippingOptionRequest;
 use Lunar\Shipping\Interfaces\ShippingRateInterface;
 use Lunar\Shipping\Models\ShippingRate;
 use Modules\Core\Shipping\Carriers\Acs\Exceptions\AcsApiException;
+use Modules\Core\Shipping\Concerns\ResolvesFixedPricing;
 use Modules\Core\Shipping\Contracts\SupportsLivePricing;
 
 class AcsRateDriver implements ShippingRateInterface, SupportsLivePricing
 {
+    use ResolvesFixedPricing;
+
     public ShippingRate $shippingRate;
 
     public function __construct(
@@ -36,39 +38,19 @@ class AcsRateDriver implements ShippingRateInterface, SupportsLivePricing
         $shippingMethod = $shippingRate->shippingMethod;
         $cart = $shippingOptionRequest->cart;
 
+        if (($shippingMethod->data['charge_by'] ?? 'cart_total') !== 'live') {
+            return $this->resolveFixedPrice($shippingRate, $shippingMethod, $cart);
+        }
+
         $postcode = $cart->shippingAddress?->postcode;
 
         if (! $postcode) {
             return null;
         }
 
-        if (($shippingRate->pricing_mode ?? 'live') === 'fixed') {
-            return $this->resolveFixedPrice($shippingRate, $shippingMethod, $cart);
-        }
-
         return $this->resolveLivePrice($shippingRate, $shippingMethod, $cart, $postcode);
     }
 
-    private function resolveFixedPrice(ShippingRate $shippingRate, $shippingMethod, $cart): ?ShippingOption
-    {
-        $subTotal = $cart->lines->sum('subTotal.value');
-
-        $pricing = Pricing::for($shippingRate)->qty($subTotal)->get();
-
-        if (! $pricing->matched) {
-            return null;
-        }
-
-        return new ShippingOption(
-            name: $shippingMethod->name ?: $this->name(),
-            description: $shippingMethod->description ?: $this->description(),
-            identifier: $shippingRate->getIdentifier(),
-            price: $pricing->matched->price,
-            taxClass: $shippingRate->getTaxClass(),
-            taxReference: $shippingRate->getTaxReference(),
-        );
-    }
-
     private function resolveLivePrice(ShippingRate $shippingRate, $shippingMethod, $cart, string $postcode): ?ShippingOption
     {
         try {