fix(purchase): unify expired checkout errors

tests/Feature/Purchase/PurchaseExpiredExceptionResponseTest.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Tests\Feature\Purchase;
+
+use App\Domains\Purchase\Exceptions\PurchaseExpiredException;
+use Illuminate\Support\Facades\Route;
+use Tests\TestCase;
+
+class PurchaseExpiredExceptionResponseTest extends TestCase
+{
+    public function test_it_returns_a_stable_api_error_for_an_expired_purchase(): void
+    {
+        Route::get('/api/test/purchase-expired', function (): never {
+            throw new PurchaseExpiredException;
+        });
+
+        $this->getJson('/api/test/purchase-expired')
+            ->assertUnprocessable()
+            ->assertExactJson([
+                'code' => 'purchase.expired',
+                'message' => __('api.purchase.expired'),
+            ]);
+    }
+}