Add application API and OpenAPI docs

app/Http/Controllers/Api/ApiController.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace App\Http\Controllers\Api;
+
+use App\Http\Controllers\Controller;
+use App\Models\User;
+use Illuminate\Http\Request;
+
+abstract class ApiController extends Controller
+{
+    protected function authenticatedUser(Request $request): User
+    {
+        $user = $request->user();
+
+        abort_if($user === null, 401);
+
+        return $user;
+    }
+}