添加search-form样式以修复查询条件布局问题

- 添加.search-form样式定义
- 确保与用户管理保持一致的布局结构

vue-frontend/src/components/RoleManagement.vue

@@ -725,6 +725,12 @@ export default {
   color: #606266;
 }
 
+.search-form {
+  display: flex;
+  flex-direction: column;
+  gap: 12px;
+}
+
 .search-row {
   display: flex;
   flex-wrap: wrap;