fix(admin-dashboard): billing workbench links use selfWithoutBack for back param

tests/Feature/AdminDashboardBillingWorkbenchLinksShouldUseSelfWithoutBackTest.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Tests\Feature;
+
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class AdminDashboardBillingWorkbenchLinksShouldUseSelfWithoutBackTest extends TestCase
+{
+    use RefreshDatabase;
+
+    protected function loginAsPlatformAdmin(): void
+    {
+        $this->seed();
+
+        $this->post('/admin/login', [
+            'email' => 'platform.admin@demo.local',
+            'password' => 'Platform@123456',
+        ])->assertRedirect('/admin');
+    }
+
+    public function test_dashboard_billing_workbench_links_should_use_self_without_back(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        // 模拟“带 back 进入仪表盘”的场景；仪表盘内部入口应仍返回 /admin（selfWithoutBack），而不是沿用 incoming back。
+        $res = $this->get('/admin?back=/admin/platform-orders');
+        $res->assertOk();
+
+        // 断言：工作台入口链接应带 back=%2Fadmin，而不是 back=%2Fadmin%2Fplatform-orders
+        $res->assertSee('back=%2Fadmin', false);
+        $res->assertDontSee('back=%2Fadmin%2Fplatform-orders', false);
+    }
+}