feat(ticket): replace the after-sale flow with a general ticket system

The old 售后 flow was an order-refund appendage: tickets were hard-bound to an
order number, users could only file them from 「我的订单」against a paid order,
and the admin action bottomed out at 「标记订单已退款」. It could not carry
account questions or feature requests that have nothing to do with an order.

Replace it with a general ticket system modelled on 魔方财务云's idcsmart_ticket:
title + department + description are required, linking an order is optional
(user's own paid orders only). Add departments, custom statuses, preset replies
and internal admin notes as four configuration surfaces. Conversation history
moves off the ticket row's JSON log into dedicated ticket_reply rows, which
unlocks quoted replies. Front end gets a 工单中心 panel under 我的服务; back end
moves from 支付中心 → 售后服务 to users.php → 工单管理.

Per CLAUDE.md's rewrite-over-compatibility rule: drop the old table, build new
ones, delete the old code. No dual paths, no data migration. The upstream
plugin's upstream/downstream delivery and internal-ticket conversion are
deliberately left out — both are multi-provider platform concerns with no
meaning on a single WordPress site.

Data: order_aftersale becomes six aksrt_ticket* tables (ticket, ticket_reply,
ticket_status, ticket_type, ticket_prereply, ticket_note). SCHEMA_VERSION
2.6.0 -> 3.0.0. Status and department seeds are idempotent; the default status
「待接单」is flagged as non-editable.

Domain: new src/Ticket/ (13 files, all under 460 lines). Attachments reuse
UserController::rest_upload_comment_image with a ticket-specific permission
callback, mirroring the existing /report/upload-image route rather than
growing a second upload path.

Notifications go through AKSRT\Messages\Message::send() and deep-link to the
right surface; email/SMS stay out of scope since the theme's mail and SMS
stacks are separate implementations.

Refund gate opens up: marking an order refunded no longer requires an in-flight
ticket, only that the order is paid.

Also generalise a hardcoded special case in tools/audit-admin-contracts.php —
schema domain inference now reads the parent directory instead of matching
"PostList" by name, so new leaf schema files need no per-name exception.

Verification:
  php tools/audit-admin-contracts.php   exit 0, errors=0
  node --test (widget-system + admin)   664 pass / 0 fail
  php -l over all new/changed files     clean
  node --check over all JS              clean
  npm run build + build:public          clean

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

assets/admin/src/constants/sections/payment.js

@@ -88,16 +88,5 @@ export const paymentSection = {
       canonicalDomain: 'payment',
       section: 'withdrawal',
     }),
-    schemaPage({
-      key: 'payment-after-sale',
-      name: 'PaymentAfterSale',
-      label: '售后策略',
-      route: '/payment/after-sale',
-      status: 'available',
-      title: '售后策略',
-      desc: '售后功能开关、申请时效、超时效提示与申请表单（预置原因、所需材料、图片上传）配置。',
-      canonicalDomain: 'payment',
-      section: 'after_sale',
-    }),
   ],
 }

assets/admin/src/constants/sections/users.js

@@ -130,5 +130,15 @@ export const usersSection = {
       canonicalDomain: 'users',
       section: 'report',
     }),
+    schemaPage({
+      key: 'users-ticket',
+      name: 'UsersTicket',
+      label: '工单中心',
+      route: '/users/ticket',
+      title: '工单中心',
+      desc: '工单功能开关、工单号前缀、提交公告与提交表单（图片上传、关联订单、催单冷却）配置；部门、状态与预设回复在 WordPress 用户菜单的「工单管理」中维护。',
+      canonicalDomain: 'users',
+      section: 'ticket',
+    }),
   ],
 }