fix(用户管理): 修复不传 realname 时查询用户列表抛 NPE 的问题

对 realname 参数增加非空判断，避免 null 值时调用 replaceAll 抛出 NullPointerException

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

jeecg-system/jeecg-system-biz/src/main/java/org/jeecg/modules/system/service/impl/HealthUserEmployeeExServiceImpl.java

@@ -192,8 +192,10 @@ public class HealthUserEmployeeExServiceImpl extends ServiceImpl<HealthUserEmplo
         }
         List<String> orgCodes = GlobalUtils.getManagedCodes(filter.getOrgCode());
         filter.setOrgCodes(orgCodes);
-        // 20260330 &middot; 名字中包含·需要转义回·
-        filter.setRealname(filter.getRealname().replaceAll("&middot;", "·"));
+        // 名字中包含·（中文间隔号）时，前端可能传入 HTML 实体 &middot;，需转义回原字符
+        if (StrUtil.isNotBlank(filter.getRealname())) {
+            filter.setRealname(filter.getRealname().replaceAll("&middot;", "·"));
+        }
         IPage<UserEmployee> userEmployeeIPage = healthUserEmployeeExMapper.queryUserEmployeeList(page, filter);
         if (CollectionUtils.isEmpty(userEmployeeIPage.getRecords())) {
             return userEmployeeIPage;