feat(orders): embed My Orders inside user center (zibll-style)

Register UC panel tab=orders with full order list/actions UI; route
aksrt_get_orders_page_url and /orders template to profile?tab=orders;
enqueue order assets when the UC orders tab is active.

inc/helpers/user-center-renderers/sidebar-commerce.php

@@ -52,8 +52,14 @@ if (empty($orders_url) && empty($show_vip) && empty($show_credit_tabs) && empty(
 	<div class="uc-sidebar__title"><?php esc_html_e('权益与消费', 'aksrt'); ?></div>
 	<div class="uc-sidebar__buttons">
 		<?php $revenue_url = function_exists('aksrt_get_revenue_page_url') ? aksrt_get_revenue_page_url() : ''; ?>
-		<?php if (!empty($orders_url)) : ?>
-			<a href="<?php echo esc_url($orders_url); ?>" class="uc-sidebar__btn">
+		<?php
+		$orders_href = !empty($orders_url)
+			? (string) $orders_url
+			: (function_exists('aksrt_get_user_center_tab_url') ? aksrt_get_user_center_tab_url('orders') : '');
+		if ($orders_href !== '') :
+			$orders_active = !empty($active_tab) && $active_tab === 'orders';
+			?>
+			<a href="<?php echo esc_url($orders_href); ?>" class="uc-sidebar__btn<?php echo $orders_active ? ' is-active' : ''; ?>" data-tab="orders">
 				<i class="fas fa-receipt" aria-hidden="true"></i>
 				<span><?php esc_html_e('我的订单', 'aksrt'); ?></span>
 			</a>