feat(platform-orders): 列表摘要增加退款总览并引入 refund_summary 扁平统计

tests/Feature/AdminPlatformOrderTest.php

@@ -37,6 +37,8 @@ class AdminPlatformOrderTest extends TestCase
             ->assertSee('最近24小时批量同步过')
             ->assertSee('可同步订单')
             ->assertSee('近24小时批量同步')
+            ->assertSee('部分退款 / 已退款')
+            ->assertSee('退款总额')
             ->assertSee('快捷筛选')
             ->assertSee('待支付')
             ->assertSee('待生效')