Site subscriptions show: build index link via BackUrl helpers

resources/views/admin/site_subscriptions/show.blade.php

@@ -27,17 +27,16 @@
 
 @php
     // 用于构建“保留当前上下文”的订阅列表跳转链接（从订阅详情跳回列表后可一键返回本订阅详情）
-    $subscriptionShowSelf = '/' . ltrim(request()->path(), '/');
-    $subscriptionShowQuery = request()->query();
-    unset($subscriptionShowQuery['back']);
-    if (count($subscriptionShowQuery) > 0) {
-        $subscriptionShowSelf .= '?' . \Illuminate\Support\Arr::query($subscriptionShowQuery);
-    }
+    // 统一收敛：订阅详情页自身（剔除 back）直接复用 BackUrl::selfWithoutBack，避免手写拼接口径漂移。
+    $subscriptionShowSelf = \App\Support\BackUrl::selfWithoutBack();
 
     $makeSubscriptionIndexUrl = function (array $query) use ($subscriptionShowSelf) {
-        $query = $query + ['back' => $subscriptionShowSelf];
+        $url = '/admin/site-subscriptions';
+        if (count($query) > 0) {
+            $url .= '?' . \Illuminate\Support\Arr::query($query);
+        }
 
-        return '/admin/site-subscriptions?' . \Illuminate\Support\Arr::query($query);
+        return \App\Support\BackUrl::withBack($url, $subscriptionShowSelf);
     };
 @endphp