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/expression-language/Token.php

@@ -0,0 +1,58 @@
+<?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\ExpressionLanguage;
+
+/**
+ * Represents a Token.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class Token
+{
+    public $value;
+    public $type;
+    public $cursor;
+
+    public const EOF_TYPE = 'end of expression';
+    public const NAME_TYPE = 'name';
+    public const NUMBER_TYPE = 'number';
+    public const STRING_TYPE = 'string';
+    public const OPERATOR_TYPE = 'operator';
+    public const PUNCTUATION_TYPE = 'punctuation';
+
+    /**
+     * @param self::*_TYPE $type
+     * @param int|null     $cursor The cursor position in the source
+     */
+    public function __construct(string $type, string|int|float|null $value, ?int $cursor)
+    {
+        $this->type = $type;
+        $this->value = $value;
+        $this->cursor = $cursor;
+    }
+
+    /**
+     * Returns a string representation of the token.
+     */
+    public function __toString(): string
+    {
+        return \sprintf('%3d %-11s %s', $this->cursor, strtoupper($this->type), $this->value);
+    }
+
+    /**
+     * Tests the current token for a type and/or a value.
+     */
+    public function test(string $type, ?string $value = null): bool
+    {
+        return $this->type === $type && (null === $value || $this->value == $value);
+    }
+}