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/phpstan/phpdoc-parser/src/Ast/AbstractNodeVisitor.php

@@ -0,0 +1,34 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\PhpDocParser\Ast;
+
+/**
+ * Inspired by https://github.com/nikic/PHP-Parser/tree/36a6dcd04e7b0285e8f0868f44bd4927802f7df1
+ *
+ * Copyright (c) 2011, Nikita Popov
+ * All rights reserved.
+ */
+abstract class AbstractNodeVisitor implements NodeVisitor // phpcs:ignore SlevomatCodingStandard.Classes.SuperfluousAbstractClassNaming.SuperfluousPrefix
+{
+
+	public function beforeTraverse(array $nodes): ?array
+	{
+		return null;
+	}
+
+	public function enterNode(Node $node)
+	{
+		return null;
+	}
+
+	public function leaveNode(Node $node)
+	{
+		return null;
+	}
+
+	public function afterTraverse(array $nodes): ?array
+	{
+		return null;
+	}
+
+}