feat(hrm): 添加流程任务审批人昵称显示功能

- 引入 UserService 依赖以获取用户信息
- 在 HrmFlowTaskVo 中新增 assigneeNickName 字段
- 查询流程任务时关联查询审批人昵称并设置到返回对象中
- 优化流程任务详情查询逻辑以支持审批人信息展示

fad-hrm/src/main/java/com/ruoyi/hrm/domain/vo/HrmFlowTaskVo.java

@@ -41,4 +41,6 @@ public class HrmFlowTaskVo implements Serializable {
     private Date createTime;
     private String updateBy;
     private Date updateTime;
+
+    private String assigneeNickName;
 }

fad-hrm/src/main/java/com/ruoyi/hrm/service/impl/HrmFlowTaskServiceImpl.java

@@ -7,6 +7,7 @@ import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.ruoyi.common.core.domain.PageQuery;
 import com.ruoyi.common.core.page.TableDataInfo;
+import com.ruoyi.common.core.service.UserService;
 import com.ruoyi.hrm.domain.*;
 import com.ruoyi.hrm.domain.bo.HrmFlowTaskBo;
 import com.ruoyi.hrm.domain.bo.HrmSealStampBo;
@@ -42,6 +43,7 @@ public class HrmFlowTaskServiceImpl implements IHrmFlowTaskService {
     private final HrmSealReqMapper sealReqMapper;
     private final HrmReimburseReqMapper reimburseReqMapper;
     private final ObjectMapper objectMapper; // Spring Boot 默认提供
+    private final UserService userService;
 
     @Override
     public HrmFlowTaskVo queryById(Long taskId) {
@@ -364,7 +366,9 @@ public class HrmFlowTaskServiceImpl implements IHrmFlowTaskService {
             .eq(HrmFlowTask::getStatus, "pending")
             .orderByDesc(HrmFlowTask::getTaskId)
             .last("limit 1");
-        return baseMapper.selectVoOne(lqw);
+        HrmFlowTaskVo hrmFlowTaskVo = baseMapper.selectVoOne(lqw);
+        hrmFlowTaskVo.setAssigneeNickName(userService.selectNickNameById(assigneeUserId));
+        return hrmFlowTaskVo;
     }
 
     private LambdaQueryWrapper<HrmFlowTask> buildQueryWrapper(HrmFlowTaskBo bo) {