feat(payment): 补齐创作分成结算 + 收尾 auth 壳层欠账

- 新增 AKSRT_Creator_Revenue：监听 aksrt_order_paid，按 share_ratio 把商品作者分成写入既有 aksrt_revenue 台账（幂等、跳过自购），闭合此前"结算引擎"延后项；管理端 /payment/revenue 与 /shop 概览自动读取。
- page-verify-email 套用 sign 壳层与站点 logo，和 reset/bind 对齐。
- modal-auth 补 close_signup 门控，与全页登录页一致。

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

templates/parts/modal-auth.php

@@ -26,6 +26,9 @@ $show_qrcode_tab = false;
 
 if (class_exists('AKSRT_Settings')) {
     $registration_open = AKSRT_Settings::registration_enabled();
+    if (method_exists('AKSRT_Settings', 'close_signup') && AKSRT_Settings::close_signup()) {
+        $registration_open = false;
+    }
     $email_verification = AKSRT_Settings::registration_requires_email_verification();
     $close_signin = AKSRT_Settings::close_signin();