Add optional owner gateway routing to Merchant.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Services/Billing/PlanEntitlementService.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace App\Services\Billing;
+
+use App\Models\User;
+use Throwable;
+
+class PlanEntitlementService
+{
+    public const CUSTOM_PAYMENT_GATEWAY = 'custom_payment_gateway';
+
+    public function __construct(private readonly BillingClient $billing) {}
+
+    public function has(User $owner, string $feature): bool
+    {
+        try {
+            return in_array($feature, (array) ($this->billing->suiteEntitlement((string) $owner->public_id)['features'] ?? []), true);
+        } catch (Throwable) {
+            return false;
+        }
+    }
+
+    public function canUseCustomPaymentGateway(User $owner): bool
+    {
+        return $this->has($owner, self::CUSTOM_PAYMENT_GATEWAY);
+    }
+}