feat: add PageTitle accessibility rule (WCAG 2.4.2)

src/Rules/PageTitle.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class PageTitle extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_2_4_2_PAGE_TITLE'; }
+    public function getDescription(): string { return 'Web pages must have a non-empty title element in the head.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::ERROR; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (strtolower($element->tagName) !== 'head') {
+            return null;
+        }
+
+        $titles = $element->getElementsByTagName('title');
+        
+        if ($titles->length === 0) {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Add a <title> element inside the <head>.'
+            );
+        }
+
+        $titleText = '';
+        $firstTitle = $titles->item(0);
+        if ($firstTitle !== null) {
+            $titleText = trim($firstTitle->textContent);
+        }
+
+        if ($titleText === '') {
+            return $this->createViolation(
+                $element,
+                $this->getDescription(),
+                'Provide descriptive text inside the <title> element.'
+            );
+        }
+
+        return null;
+    }
+}