refactor(plans): use BackUrl::withBack for create/edit/order links in index

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

@@ -154,7 +154,7 @@
             <p class="muted muted-xs">后续将从这里进入套餐详情、授权项与订阅联动。</p>
         </div>
         @php
-            $createPlanUrl = '/admin/plans/create?' . \Illuminate\Support\Arr::query(['back' => $selfWithoutBack]);
+            $createPlanUrl = \App\Support\BackUrl::withBack('/admin/plans/create', $selfWithoutBack);
         @endphp
         <a href="{!! $createPlanUrl !!}" class="btn btn-sm">新建套餐</a>
     </div>
@@ -208,12 +208,11 @@
                 </td>
                 <td>
                     @php
-                        $editPlanUrl = '/admin/plans/' . $plan->id . '/edit?' . \Illuminate\Support\Arr::query(['back' => $selfWithoutBack]);
-                        $createOrderUrl = '/admin/platform-orders/create?' . \Illuminate\Support\Arr::query([
+                        $editPlanUrl = \App\Support\BackUrl::withBack('/admin/plans/' . $plan->id . '/edit', $selfWithoutBack);
+                        $createOrderUrl = \App\Support\BackUrl::withBack('/admin/platform-orders/create?' . \Illuminate\Support\Arr::query([
                             'plan_id' => $plan->id,
                             'order_type' => 'new_purchase',
-                            'back' => $selfWithoutBack,
-                        ]);
+                        ]), $selfWithoutBack);
                     @endphp
                     <div class="actions gap-10">
                         <a href="{!! $editPlanUrl !!}" class="btn btn-secondary btn-sm">编辑</a>