feat: add payment intent handling in PurchaseController with validation and QR generation

app/Domains/Purchase/Requests/PaymentIntentRequest.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace App\Domains\Purchase\Requests;
+
+use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Validation\Rule;
+
+class PaymentIntentRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return $this->user() !== null;
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    public function rules(): array
+    {
+        return [
+            'method' => ['required', 'string', Rule::in(['qr', 'transfer'])],
+        ];
+    }
+}