update rm deadcode

app/Helpers/OrderHelper.php

@@ -2,6 +2,7 @@
 
 namespace App\Helpers;
 
+use App\Enums\Product\ProductBillingCycle;
 use App\Models\Invoice;
 use App\Models\Order;
 use Illuminate\Support\Str;
@@ -31,17 +32,14 @@ class OrderHelper
         return $number;
     }
 
-    /** Number of months a billing_cycle value represents (used for pricing and expires_at math). */
+    /**
+     * @throws \InvalidArgumentException
+     */
     public static function cycleToMonths(?string $cycle): int
     {
-        return match ($cycle) {
-            'monthly' => 1,
-            'quarterly' => 3,
-            'semi_annually' => 6,
-            'annually' => 12,
-            'biennially' => 24,
-            'triennially' => 36,
-            default => 1,
-        };
+        $enum = ProductBillingCycle::tryFrom($cycle ?? '')
+            ?? throw new \InvalidArgumentException("Unknown billing cycle: " . ($cycle ?? 'null'));
+
+        return $enum === ProductBillingCycle::ONE_TIME ? 1 : $enum->months();
     }
 }