ver. 0.294: Remove all 12 legacy autoload/shop/ classes (~2363 lines)

Complete Domain-Driven Architecture migration:
- Phase 1-4: Transport, ProductSet, Coupon, Shop, Search, Basket,
  ProductCustomField, Category, ProductAttribute, Promotion
- Phase 5: Order (~562 lines) + Product (~952 lines)
- ~20 Product methods migrated to ProductRepository
- Apilo sync migrated to OrderAdminService
- Production hotfixes: stale Redis cache (prices 0.00), unqualified
  Product:: refs in LayoutEngine, object->array template conversion
- AttributeRepository::getAttributeValueById() Redis cache added

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

templates/shop-order/mail-summary.php

@@ -64,7 +64,7 @@ echo $this -> settings['newsletter_header'];
   </thead>
   <tbody>
     <? if ( is_array( $this -> order['products'] ) ): foreach ( $this -> order['products'] as $position ):?>
-      <? $product = \shop\Product::getFromCache( $position['product_id'], $lang_id );?>
+      <? $product = (new \Domain\Product\ProductRepository($GLOBALS['mdb']))->findCached( $position['product_id'], $lang_id );?>
       <tr style="border-bottom: 1px solid #eee;">
         <td style="padding: 10px 10px 10px 0;" colspan="4">
           <?