feat(invitation): update seat allocation structure and enhance provisioning logic

database/migrations/2026_08_22_000000_add_desfile_invitation_seats.php

@@ -0,0 +1,25 @@
+<?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([
+            [
+                'sector' => 'C',
+                'row' => 3,
+                'first_seat' => 6,
+                'last_seat' => 7,
+                'type' => 'NORMAL',
+            ],
+        ]);
+    }
+
+    public function down(): void
+    {
+        // Intentionally irreversible: issued invitation tickets may already be used.
+    }
+};