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/AsyncDecoratorTrait.php

@@ -0,0 +1,41 @@
+<?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\Response\AsyncResponse;
+use Symfony\Component\HttpClient\Response\ResponseStream;
+use Symfony\Contracts\HttpClient\ResponseInterface;
+use Symfony\Contracts\HttpClient\ResponseStreamInterface;
+
+/**
+ * Eases with processing responses while streaming them.
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+trait AsyncDecoratorTrait
+{
+    use DecoratorTrait;
+
+    /**
+     * @return AsyncResponse
+     */
+    abstract public function request(string $method, string $url, array $options = []): ResponseInterface;
+
+    public function stream(ResponseInterface|iterable $responses, ?float $timeout = null): ResponseStreamInterface
+    {
+        if ($responses instanceof AsyncResponse) {
+            $responses = [$responses];
+        }
+
+        return new ResponseStream(AsyncResponse::stream($responses, $timeout, static::class));
+    }
+}