feat(ticket): 更新工单列表排序逻辑

- 实现工单状态优先级排序：pending > assigned > processing > resolved > closed
- 添加紧急程度优先级排序：urgent > high > normal > low
- 保持相同状态下按创建时间倒序排列
- 使用FIELD函数优化数据库查询排序性能
- 移除原有的简单排序规则并替换为复合排序逻辑

src/main/java/com/gxwebsoft/app/service/impl/AppTicketServiceImpl.java

@@ -81,7 +81,8 @@ public class AppTicketServiceImpl extends ServiceImpl<AppTicketMapper, AppTicket
                 .and(ObjectUtil.isNotEmpty(param.getKeywords()), q ->
                         q.like(AppTicket::getTitle, param.getKeywords())
                          .or().like(AppTicket::getTicketNo, param.getKeywords()))
-                .orderByDesc(AppTicket::getCreateTime);
+                // 状态优先级：pending > assigned > processing > resolved > closed；同状态内最新的排前
+                .last("ORDER BY FIELD(status,'pending','assigned','processing','resolved','closed','rejected'), create_time DESC");
 
         baseMapper.selectPage(page, wrapper);
         return new PageResult<>(page.getRecords(), page.getTotal());
@@ -105,8 +106,8 @@ public class AppTicketServiceImpl extends ServiceImpl<AppTicketMapper, AppTicket
                 .and(ObjectUtil.isNotEmpty(param.getKeywords()), q ->
                         q.like(AppTicket::getTitle, param.getKeywords())
                          .or().like(AppTicket::getTicketNo, param.getKeywords()))
-                .orderByAsc(AppTicket::getStatus)   // pending 排前面
-                .orderByDesc(AppTicket::getCreateTime);
+                // 状态优先级 > 紧急程度 > 最新提交时间
+                .last("ORDER BY FIELD(status,'pending','assigned','processing','resolved','closed','rejected'), FIELD(priority,'urgent','high','normal','low'), create_time DESC");
 
         baseMapper.selectPage(page, wrapper);
         return new PageResult<>(page.getRecords(), page.getTotal());