fix: 修复编译错误

- 添加 DemandTypeMapper 依赖注入
- 修复 User.getDeptId() 方法名

backend/src/main/java/com/designhub/service/TaskService.java

@@ -15,6 +15,7 @@ import com.designhub.mapper.TaskMapper;
 import com.designhub.mapper.BrandMapper;
 import com.designhub.mapper.CategoryMapper;
 import com.designhub.mapper.PlatformMapper;
+import com.designhub.mapper.DemandTypeMapper;
 import com.designhub.vo.DashboardStatsVO;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
@@ -46,6 +47,7 @@ public class TaskService {
     private final BrandMapper brandMapper;
     private final CategoryMapper categoryMapper;
     private final PlatformMapper platformMapper;
+    private final DemandTypeMapper demandTypeMapper;
     private final TeamScorePoolService teamScorePoolService;
     private final ConfigService configService;
     private final DelayPenaltyService delayPenaltyService;
@@ -675,7 +677,7 @@ public class TaskService {
      */
     public Long getUserDeptId(Long userId) {
         User user = userService.getUserById(userId);
-        return user != null ? user.getDepartmentId() : null;
+        return user != null ? user.getDeptId() : null;
     }
 
     /**