平台订单创建页：去订阅管理选择订阅的 back 保持 require_subscription=1 并新增测试

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

@@ -177,7 +177,16 @@
                     $jumpBase .= '?' . \Illuminate\Support\Arr::query($jumpQuery);
                 }
 
-                $jumpUrl = \App\Support\BackUrl::withBack($jumpBase, \App\Support\BackUrl::selfWithoutBack());
+                $createSelfForBack = \App\Support\BackUrl::selfWithoutBack();
+                // 若 require_subscription 来自 old input（校验失败回填），当前 URL 可能不带 query，
+                // 此时也需要把 require_subscription=1 写回到 back，避免“去订阅管理选择订阅”回来后治理口径丢失。
+                if (($requireSubscription ?? false) || ((string) old('require_subscription', '') === '1')) {
+                    $createSelfForBack = \App\Support\BackUrl::currentPathWithQuery([
+                        'require_subscription' => 1,
+                    ], '');
+                }
+
+                $jumpUrl = \App\Support\BackUrl::withBack($jumpBase, $createSelfForBack);
             @endphp
 
             @if(($requireSubscription ?? false) && $jumpUrl)