fix: 修复用户管理列表字段显示问题

将后端返回的下划线命名字段转换为驼峰格式：
- user_id → userId
- user_name → userName
- nick_name → nickName
- dept_name → dept.deptName

用户管理功能正常

backend/pangu-system/src/main/java/com/pangu/system/controller/SysUserController.java

@@ -71,10 +71,30 @@ public class SysUserController extends BaseController {
         
         List<Map<String, Object>> rows = jdbcTemplate.queryForList(sql.toString(), params.toArray());
         
+        // 转换字段名为驼峰格式，并包装 dept 对象
+        List<Map<String, Object>> result = new ArrayList<>();
+        for (Map<String, Object> row : rows) {
+            Map<String, Object> item = new HashMap<>();
+            item.put("userId", row.get("user_id"));
+            item.put("userName", row.get("user_name"));
+            item.put("nickName", row.get("nick_name"));
+            item.put("email", row.get("email"));
+            item.put("phonenumber", row.get("phonenumber"));
+            item.put("sex", row.get("sex"));
+            item.put("status", row.get("status"));
+            item.put("createTime", row.get("create_time"));
+            // 前端期望 dept.deptName 格式
+            Map<String, Object> dept = new HashMap<>();
+            dept.put("deptId", row.get("dept_id"));
+            dept.put("deptName", row.get("dept_name"));
+            item.put("dept", dept);
+            result.add(item);
+        }
+        
         TableDataInfo dataInfo = new TableDataInfo();
         dataInfo.setCode(200);
         dataInfo.setMsg("查询成功");
-        dataInfo.setRows(rows);
+        dataInfo.setRows(result);
         dataInfo.setTotal(total != null ? total : 0);
         return dataInfo;
     }