Revived API POST /api/v1/captcha.

Captcha validation has been adjusted.

app/Repositories/CaptchaRepository.php

@@ -0,0 +1,13 @@
+<?php declare(strict_types=1);
+
+namespace App\Repositories;
+
+use App\Models\Captcha;
+
+final class CaptchaRepository
+{
+    public function getCaptchaById(int $id): ?Captcha
+    {
+        return Captcha::query()->where('id', $id)->first();
+    }
+}