fix: resolve PHPStan level 9 errors and bump version to v3.1.3

src/Rules/NestedInteractive.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use DOMXPath;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class NestedInteractive extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_4_1_2_NestedInteractive'; }
+    public function getDescription(): string { return 'Checks for nested interactive elements.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::ERROR; }
+    public function getLevel(): int { return 3; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        $tag = strtolower($element->tagName);
+        if (!in_array($tag, ['a', 'button'])) {
+            return null;
+        }
+        
+        $doc = $element->ownerDocument;
+        if ($doc === null) {
+            return null;
+        }
+        $xpath = new DOMXPath($doc);
+        $interactives = $xpath->query('.//a | .//button | .//input | .//select | .//textarea', $element);
+        
+        if ($interactives !== false && $interactives->length > 0) {
+            return $this->createViolation(
+                $element,
+                "İç içe geçmiş etkileşimli öğeler bulundu (<{$tag}> içerisinde).",
+                'Ensure interactive controls are not nested.'
+            );
+        }
+        
+        return null;
+    }
+}