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/http-client/DnsResolvingHttpClient.php

@@ -0,0 +1,97 @@
+<?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\HttpClient;
+
+use Symfony\Component\HttpClient\Internal\FollowRedirectsTrait;
+use Symfony\Contracts\HttpClient\HttpClientInterface;
+use Symfony\Contracts\HttpClient\ResponseInterface;
+use Symfony\Contracts\Service\ResetInterface;
+
+/**
+ * Decorator that resolves host names using a custom resolver before delegating to the transport.
+ *
+ * The resolver is called for the requested host and for the host of every followed redirect. When it
+ * returns an IP address, the result is injected into the "resolve" option so that the transport connects
+ * to that IP without performing its own DNS resolution. When it returns null, the transport's default
+ * DNS resolution is used. Hosts that are already in the "resolve" option or that are IP addresses are
+ * not passed to it.
+ *
+ * Note that using this decorator opts out of the asynchronous and cached DNS resolution that the curl
+ * and amphp transports provide; the resolver is responsible for any caching it needs.
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+final class DnsResolvingHttpClient implements HttpClientInterface, ResetInterface
+{
+    use AsyncDecoratorTrait;
+    use FollowRedirectsTrait;
+    use HttpClientTrait;
+
+    private array $defaultOptions = self::OPTIONS_DEFAULTS;
+
+    /** @var callable(string): ?string */
+    private $resolver;
+
+    /**
+     * @param callable(string $host): ?string $resolver Returns the IP address the given host name should resolve to,
+     *                                                  or null to let the transport perform its default DNS resolution
+     */
+    public function __construct(
+        private HttpClientInterface $client,
+        callable $resolver,
+    ) {
+        $this->resolver = $resolver;
+    }
+
+    public function request(string $method, string $url, array $options = []): ResponseInterface
+    {
+        [$url, $options] = self::prepareRequest($method, $url, $options, $this->defaultOptions, true);
+
+        $host = parse_url($url['authority'], \PHP_URL_HOST);
+        $url = implode('', $url);
+
+        $resolver = $this->resolver;
+        $resolve = static function (string $host, string $url, array &$options) use ($resolver): void {
+            if (isset($options['resolve'][$host]) || false !== filter_var(trim($host, '[]'), \FILTER_VALIDATE_IP)) {
+                return;
+            }
+
+            if (null !== $ip = $resolver($host)) {
+                $options['resolve'][$host] = $ip;
+            }
+        };
+
+        $resolve($host, $url, $options);
+
+        return $this->followRedirects($method, $url, $host, $options, $resolve);
+    }
+
+    public function withOptions(array $options): static
+    {
+        $clone = clone $this;
+        $clone->client = $this->client->withOptions($options);
+        $clone->defaultOptions = self::mergeDefaultOptions($options, $this->defaultOptions);
+
+        return $clone;
+    }
+
+    public function reset(): void
+    {
+        if ($this->resolver instanceof ResetInterface) {
+            $this->resolver->reset();
+        }
+
+        if ($this->client instanceof ResetInterface) {
+            $this->client->reset();
+        }
+    }
+}