feat(invitation): implement InvitationPurchaseProvisioner and related migration and seeder updates

database/migrations/2026_08_19_030000_create_desfile_invitation_purchase.php

@@ -0,0 +1,17 @@
+<?php
+
+use App\Domains\Desfile\Services\InvitationPurchaseProvisioner;
+use Illuminate\Database\Migrations\Migration;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        app(InvitationPurchaseProvisioner::class)->provision();
+    }
+
+    public function down(): void
+    {
+        // Intentionally irreversible: issued invitation tickets may already be used.
+    }
+};