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/phpdocumentor/guides/src/NodeRenderers/Html/AdmonitionNodeRenderer.php

@@ -0,0 +1,59 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of phpDocumentor.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ *
+ * @link https://phpdoc.org
+ */
+
+namespace phpDocumentor\Guides\NodeRenderers\Html;
+
+use InvalidArgumentException;
+use phpDocumentor\Guides\NodeRenderers\NodeRenderer;
+use phpDocumentor\Guides\Nodes\AdmonitionNode;
+use phpDocumentor\Guides\Nodes\Node;
+use phpDocumentor\Guides\RenderContext;
+use phpDocumentor\Guides\TemplateRenderer;
+
+use function implode;
+use function is_a;
+
+/** @implements NodeRenderer<AdmonitionNode> */
+class AdmonitionNodeRenderer implements NodeRenderer
+{
+    public function __construct(private readonly TemplateRenderer $renderer)
+    {
+    }
+
+    public function supports(string $nodeFqcn): bool
+    {
+        return $nodeFqcn === AdmonitionNode::class || is_a($nodeFqcn, AdmonitionNode::class, true);
+    }
+
+    public function render(Node $node, RenderContext $renderContext): string
+    {
+        if ($node instanceof AdmonitionNode === false) {
+            throw new InvalidArgumentException('Node must be an instance of ' . AdmonitionNode::class);
+        }
+
+        $classes = $node->getClasses();
+
+        return $this->renderer->renderTemplate(
+            $renderContext,
+            'body/admonition.html.twig',
+            [
+                'name' => $node->getName(),
+                'text' => $node->getText(),
+                'title' => $node->getTitle(),
+                'isTitled' => $node->isTitled(),
+                'class' => implode(' ', $classes),
+                'node' => $node->getValue(),
+            ],
+        );
+    }
+}