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/nikic/php-parser/lib/PhpParser/Node/UseItem.php

@@ -0,0 +1,55 @@
+<?php declare(strict_types=1);
+
+namespace PhpParser\Node;
+
+use PhpParser\Node;
+use PhpParser\NodeAbstract;
+use PhpParser\Node\Stmt\Use_;
+
+class UseItem extends NodeAbstract {
+    /**
+     * @var Use_::TYPE_* One of the Stmt\Use_::TYPE_* constants. Will only differ from TYPE_UNKNOWN for mixed group uses
+     */
+    public int $type;
+    /** @var Node\Name Namespace, class, function or constant to alias */
+    public Name $name;
+    /** @var Identifier|null Alias */
+    public ?Identifier $alias;
+
+    /**
+     * Constructs an alias (use) item node.
+     *
+     * @param Node\Name $name Namespace/Class to alias
+     * @param null|string|Identifier $alias Alias
+     * @param Use_::TYPE_* $type Type of the use element (for mixed group use only)
+     * @param array<string, mixed> $attributes Additional attributes
+     */
+    public function __construct(Node\Name $name, $alias = null, int $type = Use_::TYPE_UNKNOWN, array $attributes = []) {
+        $this->attributes = $attributes;
+        $this->type = $type;
+        $this->name = $name;
+        $this->alias = \is_string($alias) ? new Identifier($alias) : $alias;
+    }
+
+    public function getSubNodeNames(): array {
+        return ['type', 'name', 'alias'];
+    }
+
+    /**
+     * Get alias. If not explicitly given this is the last component of the used name.
+     */
+    public function getAlias(): Identifier {
+        if (null !== $this->alias) {
+            return $this->alias;
+        }
+
+        return new Identifier($this->name->getLast());
+    }
+
+    public function getType(): string {
+        return 'UseItem';
+    }
+}
+
+// @deprecated compatibility alias
+class_alias(UseItem::class, Stmt\UseUse::class);