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/Loader/Configurator/Traits/ParentTrait.php

@@ -0,0 +1,46 @@
+<?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\Loader\Configurator\Traits;
+
+use Symfony\Component\DependencyInjection\ChildDefinition;
+use Symfony\Component\DependencyInjection\Exception\InvalidArgumentException;
+
+trait ParentTrait
+{
+    /**
+     * Sets the Definition to inherit from.
+     *
+     * @return $this
+     *
+     * @throws InvalidArgumentException when parent cannot be set
+     */
+    final public function parent(string $parent): static
+    {
+        if (!$this->allowParent) {
+            throw new InvalidArgumentException(\sprintf('A parent cannot be defined when either "_instanceof" or "_defaults" are also defined for service prototype "%s".', $this->id));
+        }
+
+        if ($this->definition instanceof ChildDefinition) {
+            $this->definition->setParent($parent);
+        } else {
+            // cast Definition to ChildDefinition
+            $definition = serialize($this->definition);
+            $definition = substr_replace($definition, '53', 2, 2);
+            $definition = substr_replace($definition, 'Child', 44, 0);
+            $definition = unserialize($definition);
+
+            $this->definition = $definition->setParent($parent);
+        }
+
+        return $this;
+    }
+}