feat(shop): 交易中心壳层 1:1 统一购物车/订单/收益

抽出 commerce header 与二级导航，购物车/订单/收益共用主站交易中心壳层；收益 stats 轻量化，降低独立电商后台观感。

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

inc/classes/scripts-traits/trait-aksrt-scripts-part-1b.php

@@ -301,6 +301,22 @@ trait AKSRT_Scripts_Part_1b {
             );
         }
 
+        // 交易中心共享壳层（购物车 / 订单 / 收益）
+        $is_commerce_center = is_page_template('templates/pages/page-orders.php')
+            || is_page_template('templates/pages/page-cart.php')
+            || is_page_template('templates/pages/page-revenue.php');
+        if ($is_commerce_center) {
+            $commerce_css = get_template_directory() . '/assets/css/routes/commerce.css';
+            if (file_exists($commerce_css)) {
+                wp_enqueue_style(
+                    'aksrt-commerce-shell',
+                    $base_uri . '/assets/css/routes/commerce.css',
+                    ['aksrt-tokens'],
+                    (string) filemtime($commerce_css)
+                );
+            }
+        }
+
         // 订单中心页
         if (is_page_template('templates/pages/page-orders.php')) {
             wp_enqueue_style(