Add Rector & various upgrades

rector.php

@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use Rector\Set\ValueObject\LevelSetList;
+use Rector\Set\ValueObject\SetList;
+use Rector\TypeDeclaration\Rector\ClassMethod\ReturnTypeFromStrictNativeCallRector;
+use RectorLaravel\Set\LaravelSetList;
+
+return static function (RectorConfig $rectorConfig): void {
+    $rectorConfig->paths([
+        __DIR__.'/app',
+        __DIR__.'/tests',
+    ]);
+
+    $rectorConfig->rules([
+        ReturnTypeFromStrictNativeCallRector::class,
+    ]);
+
+    $rectorConfig->sets([
+        SetList::CODE_QUALITY,
+        LevelSetList::UP_TO_PHP_83,
+        LaravelSetList::LARAVEL_100,
+    ]);
+};