refactor(tickets): 删除工单处理功能及相关导航入口

- 从控制台导航中移除工单管理菜单项
- 从开发者导航中移除工单处理菜单项
- 完全删除工单处理页面及其代码实现
- 移除所有与工单列表、详情、回复和分配相关的UI组件和逻辑
- 清理工单处理相关的样式和API调用代码

app/config/developer-nav.ts

@@ -47,5 +47,4 @@ export const developerNav: DeveloperNavItem[] = [
 
   // 帮助
   { key: 'developer-support', label: '支持与反馈', to: '/developer/support', icon: '💬', group: '帮助' },
-  { key: 'developer-tickets', label: '工单处理', to: '/developer/tickets', icon: '🎫', group: '帮助', badge: 'NEW' },
 ]