refactor: BackUrl::selfWithoutBack 统一 selfWithoutBack 构造并修复 currentQuery 依赖

resources/views/admin/platform_orders/index.blade.php

@@ -10,12 +10,10 @@
     $SYNC_FAILED_REASON_TRUNCATE_LEN = (int) config('saasshop.platform_orders.sync_failed_reason_display_truncate_len', 60);
 
     // back 参数用于“返回上一页（保留上下文）”，但 back 本身不应再包含 back（避免无限嵌套导致 URL 膨胀）
+    $selfWithoutBack = \App\Support\BackUrl::selfWithoutBack();
+
     $currentQuery = request()->query();
     unset($currentQuery['back']);
-    $selfWithoutBack = '/' . ltrim(request()->path(), '/');
-    if (count($currentQuery) > 0) {
-        $selfWithoutBack .= '?' . \Illuminate\Support\Arr::query($currentQuery);
-    }
 
     // back 安全护栏（全页通用）：
     // - 仅允许站内相对路径（/ 开头）