refactor: Cleanup git state - commit all staged changes

Major refactoring cleanup:
- Add new controller architecture (class-controller-*.php)
- Add new settings-v2 UI (views/settings-v2/)
- Add new CSS architecture (agentic-sidebar.css, tokens)
- Add esbuild build pipeline (scripts/build.js, package.json)
- Add composer dependencies (vendor/)
- Add frontend src directory (assets/js/src/index.jsx)
- Add documentation files
- Remove old/obsolete files (class-settings.php, old CSS)

This commits all pending changes from previous refactoring efforts.

vendor/symfony/property-info/Extractor/SerializerExtractor.php

@@ -0,0 +1,52 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\PropertyInfo\Extractor;
+
+use Symfony\Component\PropertyInfo\PropertyListExtractorInterface;
+use Symfony\Component\Serializer\Mapping\Factory\ClassMetadataFactoryInterface;
+
+/**
+ * Lists available properties using Symfony Serializer Component metadata.
+ *
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ *
+ * @final
+ */
+class SerializerExtractor implements PropertyListExtractorInterface
+{
+    public function __construct(
+        private readonly ClassMetadataFactoryInterface $classMetadataFactory,
+    ) {
+    }
+
+    public function getProperties(string $class, array $context = []): ?array
+    {
+        if (!\array_key_exists('serializer_groups', $context) || (null !== $context['serializer_groups'] && !\is_array($context['serializer_groups']))) {
+            return null;
+        }
+
+        if (!$this->classMetadataFactory->hasMetadataFor($class)) {
+            return null;
+        }
+
+        $properties = [];
+        $serializerClassMetadata = $this->classMetadataFactory->getMetadataFor($class);
+
+        foreach ($serializerClassMetadata->getAttributesMetadata() as $serializerAttributeMetadata) {
+            if (!$serializerAttributeMetadata->isIgnored() && (null === $context['serializer_groups'] || \in_array('*', $context['serializer_groups'], true) || array_intersect($serializerAttributeMetadata->getGroups(), $context['serializer_groups']))) {
+                $properties[] = $serializerAttributeMetadata->getName();
+            }
+        }
+
+        return $properties;
+    }
+}