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/Compiler/ServiceReferenceGraphNode.php

@@ -0,0 +1,114 @@
+<?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\Compiler;
+
+use Symfony\Component\DependencyInjection\Alias;
+use Symfony\Component\DependencyInjection\Definition;
+
+/**
+ * Represents a node in your service graph.
+ *
+ * Value is typically a definition, or an alias.
+ *
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ */
+class ServiceReferenceGraphNode
+{
+    private string $id;
+    private array $inEdges = [];
+    private array $outEdges = [];
+    private mixed $value;
+
+    public function __construct(string $id, mixed $value)
+    {
+        $this->id = $id;
+        $this->value = $value;
+    }
+
+    /**
+     * @return void
+     */
+    public function addInEdge(ServiceReferenceGraphEdge $edge)
+    {
+        $this->inEdges[] = $edge;
+    }
+
+    /**
+     * @return void
+     */
+    public function addOutEdge(ServiceReferenceGraphEdge $edge)
+    {
+        $this->outEdges[] = $edge;
+    }
+
+    /**
+     * Checks if the value of this node is an Alias.
+     */
+    public function isAlias(): bool
+    {
+        return $this->value instanceof Alias;
+    }
+
+    /**
+     * Checks if the value of this node is a Definition.
+     */
+    public function isDefinition(): bool
+    {
+        return $this->value instanceof Definition;
+    }
+
+    /**
+     * Returns the identifier.
+     */
+    public function getId(): string
+    {
+        return $this->id;
+    }
+
+    /**
+     * Returns the in edges.
+     *
+     * @return ServiceReferenceGraphEdge[]
+     */
+    public function getInEdges(): array
+    {
+        return $this->inEdges;
+    }
+
+    /**
+     * Returns the out edges.
+     *
+     * @return ServiceReferenceGraphEdge[]
+     */
+    public function getOutEdges(): array
+    {
+        return $this->outEdges;
+    }
+
+    /**
+     * Returns the value of this Node.
+     */
+    public function getValue(): mixed
+    {
+        return $this->value;
+    }
+
+    /**
+     * Clears all edges.
+     *
+     * @return void
+     */
+    public function clear()
+    {
+        $this->inEdges = $this->outEdges = [];
+    }
+}