feat(user-center): add cash wallet balance separate from credits

Introduce AKSRT_Balance (user_meta aksrt_balance + balance_log) for
Zibll-like pay_balance wallet. User center assets panel shows wallet
and points; balance gateway/card-pass/refunds credit cash when enabled.

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

@@ -9,7 +9,7 @@
 
 defined('ABSPATH') || exit;
 
-if (empty($orders_url) && empty($show_vip) && empty($show_credit_tabs)) {
+if (empty($orders_url) && empty($show_vip) && empty($show_credit_tabs) && empty($balance_enabled)) {
 	return;
 }
 ?>