update email template

app/Integrations/Whmcs/Support/OrderIdResolver.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace App\Integrations\Whmcs\Support;
+
+use Illuminate\Support\Facades\DB;
+
+/**
+ * Resolves a WHMCS `tblorders.id` to the matching local `orders.id` via `orders.legacy_id`.
+ * Orders must be synced (whmcs:sync-orders) before invoices for this to find anything.
+ */
+class OrderIdResolver
+{
+    /** @var array<int, int>|null legacy order id => local order id */
+    private static ?array $map = null;
+
+    public function resolve(int $whmcsOrderId): ?int
+    {
+        self::$map ??= DB::table('orders')->whereNotNull('legacy_id')->pluck('id', 'legacy_id')->all();
+
+        return self::$map[$whmcsOrderId] ?? null;
+    }
+}