Route event registrations through Ladill Pay API.

Ticket and contribution checkouts use platform Pay for fees and wallet settlement, with legacy QREP-* fallback via Billing.

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

database/migrations/2026_06_08_130000_add_pay_order_id_to_qr_event_registrations_table.php

@@ -0,0 +1,22 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::table('qr_event_registrations', function (Blueprint $table) {
+            $table->unsignedBigInteger('pay_order_id')->nullable()->after('id');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('qr_event_registrations', function (Blueprint $table) {
+            $table->dropColumn('pay_order_id');
+        });
+    }
+};