feat: remove shop feature (Phase 2)

Delete all shop domain classes, controllers, schema builders, templates,
JS/CSS, admin SPA pages, and shop-only payment classes (Shipping,
AfterSale, Discount). Remove shop-only DB table definitions (product_variant,
after_sale, order_shipping, card_key) from migrator and add their DROP
to uninstall.php. Clean up shared files:

- Remove aksrt_product CPT + taxonomies from Setup.php
- Remove shop rewrite rules/query vars/template redirect from SetupPart2.php
- Remove shop widget areas from SetupPart1.php
- Remove shop enqueues from ScriptsPart1b.php
- Remove sepakerator-aksrt-shop from SetupPart2.php
- Remove get_shop_settings facade (delete ForumShop.php, clean DomainGroups.php)
- Remove ORDER_PRODUCT_SHOP constant from DomainModel.php
- Remove Shop::class fallback branches from UserOrders.php, OrderCenterRest.php
- Remove shipping/after-sale branches from OrderRepositoryAdmin.php, PayMenus.php, PayOrders.php
- Remove shop product widgets from widgets-register.php
- Remove cart page from template-registry.php, routing.php, ScriptsPart2.php
- Remove cart UI from sidebar-nav.php, profile-orders.php, sidebar-orders.php
- Clean up order-center.js (remove rebuy/cartUrl/receipt/after-sale handlers)
- Remove aksrt_get_cart_page_url/product_page/product_edit from transactions.php
- Clean up aksrt_product_cat references in Coupon.php, PayCoupons.php

Shared payment/order/credits/content-pay stack fully retained.

src/AKSRT/Admin/Native/PayMenus.php

@@ -74,28 +74,6 @@ class PayMenus {
                     wp_die(esc_html__('下载记录模块未初始化。', 'aksrt'));
                 },
             ],
-            'shipping' => [
-                'slug'     => 'aksrt_shipping',
-                'title'    => __('发货及物流', 'aksrt'),
-                'callback' => static function (): void {
-                    if (class_exists('AKSRT\\Admin\\Native\\PayShipping')) {
-                        PayShipping::get_instance()->render_shipping_page();
-                        return;
-                    }
-                    wp_die(esc_html__('物流模块未初始化。', 'aksrt'));
-                },
-            ],
-            'after_sale' => [
-                'slug'     => 'aksrt_after_sale',
-                'title'    => __('售后管理', 'aksrt'),
-                'callback' => static function (): void {
-                    if (class_exists('AKSRT\\Admin\\Native\\PayAfterSale')) {
-                        PayAfterSale::get_instance()->render_after_sale_page();
-                        return;
-                    }
-                    wp_die(esc_html__('售后模块未初始化。', 'aksrt'));
-                },
-            ],
             'coupons' => [
                 'slug'     => 'aksrt_coupons',
                 'title'    => __('优惠码', 'aksrt'),
@@ -203,23 +181,6 @@ class PayMenus {
                 echo '</div>';
             }
         }
-
-        if ($page !== 'aksrt_after_sale' && class_exists('\AKSRT\Payment\AfterSale')) {
-            $as_stats = \AKSRT\Payment\AfterSale::get_instance()->get_stats();
-            $pending_as = (int) ($as_stats['pending'] ?? 0);
-            if ($pending_as > 0) {
-                $url = admin_url('admin.php?page=aksrt_after_sale&status=pending');
-                echo '<div class="notice notice-info is-dismissible">';
-                echo '<h3>' . esc_html__('售后工单待处理', 'aksrt') . '</h3>';
-                echo '<p>' . esc_html(sprintf(
-                    /* translators: %d: pending after-sale count */
-                    __('您有 %d 个售后工单待处理', 'aksrt'),
-                    $pending_as
-                )) . '</p>';
-                echo '<p><a class="button button-primary" href="' . esc_url($url) . '">' . esc_html__('去处理', 'aksrt') . '</a></p>';
-                echo '</div>';
-            }
-        }
     }
 
     private function ensure_cap(): void {
@@ -255,17 +216,12 @@ class PayMenus {
             ? \AKSRT\Payment\ChargeCard::get_instance()->get_stats()
             : [];
 
-        echo '<p class="description">' . esc_html__('运营数据入口（对齐 zibll 商城中心）。配置项仍在 AKSRT 主题设置 SPA。', 'aksrt') . '</p>';
+        echo '<p class="description">' . esc_html__('运营数据入口。配置项仍在 AKSRT 主题设置 SPA。', 'aksrt') . '</p>';
 
         echo '<div class="aksrt-pay-stats" style="display:flex;flex-wrap:wrap;gap:16px;margin:20px 0;">';
-        $pending_ship = 0;
-        if (class_exists('\AKSRT\Payment\OrderRepository')) {
-            $pending_ship = (int) (\AKSRT\Payment\OrderRepository::get_instance()->get_pending_shipment_orders(['limit' => 1])['total'] ?? 0);
-        }
         $this->stat_card(__('订单总数', 'aksrt'), (string) (int) ($order_stats['total'] ?? 0), $this->page_url('aksrt_orders'));
         $this->stat_card(__('待支付', 'aksrt'), (string) (int) ($order_stats['pending'] ?? 0), $this->page_url('aksrt_orders', ['status' => 'pending']));
         $this->stat_card(__('已支付', 'aksrt'), (string) (int) ($order_stats['paid'] ?? 0), $this->page_url('aksrt_orders', ['status' => 'paid']));
-        $this->stat_card(__('待发货', 'aksrt'), (string) $pending_ship, $this->page_url('aksrt_shipping', ['view' => 'pending']));
         $this->stat_card(__('营收', 'aksrt'), number_format((float) ($order_stats['revenue'] ?? 0), 2), $this->page_url('aksrt_orders'));
         $this->stat_card(__('待审提现', 'aksrt'), (string) (int) ($withdraw_stats['pending'] ?? 0), $this->page_url('aksrt_withdraw', ['status' => 'pending']));
         $this->stat_card(__('可用卡密', 'aksrt'), (string) (int) ($card_stats['active'] ?? 0), $this->page_url('aksrt_charge_cards', ['status' => 'active']));