Stage 5i: migrate CatalogPricingRule + post-Stage 5 fixes

CatalogPricingRule moves to src/:
- craft\commerce\models\CatalogPricingRule → CraftCms\Commerce\Catalog\Models\CatalogPricingRule

Key swaps:
- craft\base\Model → CraftCms\Cms\Component\Component
- Yii2 defineRules() → Laravel getRules() with Rule::in() for 'apply'
- I18N::getFormatter()->asPercent() / Conditions::createCondition() facades
- CraftCms\Cms\Support\Json::decodeIfJson()

Post-Stage 5 fixes:
- Fix infinite recursion in ShippingMethodOrderCondition,
  ShippingRuleOrderCondition, DiscountOrderCondition config() methods.
  $this->toArray(['storeId']) was calling getObjectVars() which triggers
  the PHP 8.4 $config property hook getter, recursing into config().
  Replaced with explicit ['storeId' => $this->storeId].

Also adds CraftCms\Commerce\Base\EnumHelpersTrait (companion to the
Stage 1 enums, missed at the time) and the WIP changelog covering
stages 1–5.

Legacy CatalogPricingRule becomes a class_alias stub.

Author: lukeholder

CHANGELOG-WIP.md

@@ -34,7 +34,7 @@ protected function defineRules(): array
      */
     protected function config(): array
     {
-        return array_merge(parent::config(), $this->toArray(['storeId']));
+        return array_merge(parent::config(), ['storeId' => $this->storeId]);
     }
 
     /**

src-yii2/elements/conditions/orders/DiscountOrderCondition.php

@@ -31,7 +31,7 @@ class ShippingMethodOrderCondition extends OrderCondition implements HasStoreInt
     /**
      * @inheritdoc
      */
-    protected function defineRules(): array
+    public function defineRules(): array
     {
         $rules = parent::defineRules();
         $rules[] = [['storeId'], 'safe'];
@@ -44,7 +44,7 @@ protected function defineRules(): array
      */
     protected function config(): array
     {
-        return array_merge(parent::config(), $this->toArray(['storeId']));
+        return array_merge(parent::config(), ['storeId' => $this->storeId]);
     }
 
     /**

src-yii2/elements/conditions/orders/ShippingMethodOrderCondition.php

@@ -44,7 +44,7 @@ protected function defineRules(): array
      */
     protected function config(): array
     {
-        return array_merge(parent::config(), $this->toArray(['storeId']));
+        return array_merge(parent::config(), ['storeId' => $this->storeId]);
     }
 
     /**