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/dependency-injection/Loader/Configurator/InstanceofConfigurator.php

@@ -0,0 +1,50 @@
+<?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\DependencyInjection\Loader\Configurator;
+
+use Symfony\Component\DependencyInjection\Definition;
+
+/**
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+class InstanceofConfigurator extends AbstractServiceConfigurator
+{
+    use Traits\AutowireTrait;
+    use Traits\BindTrait;
+    use Traits\CallTrait;
+    use Traits\ConfiguratorTrait;
+    use Traits\ConstructorTrait;
+    use Traits\LazyTrait;
+    use Traits\PropertyTrait;
+    use Traits\PublicTrait;
+    use Traits\ShareTrait;
+    use Traits\TagTrait;
+
+    public const FACTORY = 'instanceof';
+
+    private ?string $path;
+
+    public function __construct(ServicesConfigurator $parent, Definition $definition, string $id, ?string $path = null)
+    {
+        parent::__construct($parent, $definition, $id, []);
+
+        $this->path = $path;
+    }
+
+    /**
+     * Defines an instanceof-conditional to be applied to following service definitions.
+     */
+    final public function instanceof(string $fqcn): self
+    {
+        return $this->parent->instanceof($fqcn);
+    }
+}