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/Extension/ExtensionTrait.php

@@ -0,0 +1,69 @@
+<?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\Extension;
+
+use Symfony\Component\Config\Builder\ConfigBuilderGenerator;
+use Symfony\Component\Config\FileLocator;
+use Symfony\Component\Config\Loader\DelegatingLoader;
+use Symfony\Component\Config\Loader\LoaderResolver;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Loader\ClosureLoader;
+use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
+use Symfony\Component\DependencyInjection\Loader\DirectoryLoader;
+use Symfony\Component\DependencyInjection\Loader\GlobFileLoader;
+use Symfony\Component\DependencyInjection\Loader\IniFileLoader;
+use Symfony\Component\DependencyInjection\Loader\PhpFileLoader;
+use Symfony\Component\DependencyInjection\Loader\XmlFileLoader;
+use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
+
+/**
+ * @author Yonel Ceruto <yonelceruto@gmail.com>
+ */
+trait ExtensionTrait
+{
+    private function executeConfiguratorCallback(ContainerBuilder $container, \Closure $callback, ConfigurableExtensionInterface $subject): void
+    {
+        $env = $container->getParameter('kernel.environment');
+        $loader = $this->createContainerLoader($container, $env);
+        $file = (new \ReflectionObject($subject))->getFileName();
+        $bundleLoader = $loader->getResolver()->resolve($file);
+        if (!$bundleLoader instanceof PhpFileLoader) {
+            throw new \LogicException('Unable to create the ContainerConfigurator.');
+        }
+        $bundleLoader->setCurrentDir(\dirname($file));
+        $instanceof = &\Closure::bind(fn &() => $this->instanceof, $bundleLoader, $bundleLoader)();
+
+        try {
+            $callback(new ContainerConfigurator($container, $bundleLoader, $instanceof, $file, $file, $env));
+        } finally {
+            $instanceof = [];
+            $bundleLoader->registerAliasesForSinglyImplementedInterfaces();
+        }
+    }
+
+    private function createContainerLoader(ContainerBuilder $container, string $env): DelegatingLoader
+    {
+        $buildDir = $container->getParameter('kernel.build_dir');
+        $locator = new FileLocator();
+        $resolver = new LoaderResolver([
+            new XmlFileLoader($container, $locator, $env),
+            new YamlFileLoader($container, $locator, $env),
+            new IniFileLoader($container, $locator, $env),
+            new PhpFileLoader($container, $locator, $env, new ConfigBuilderGenerator($buildDir)),
+            new GlobFileLoader($container, $locator, $env),
+            new DirectoryLoader($container, $locator, $env),
+            new ClosureLoader($container, $env),
+        ]);
+
+        return new DelegatingLoader($resolver);
+    }
+}