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/Resources/bin/generate_operator_regex.php

@@ -0,0 +1,31 @@
+<?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.
+ */
+
+if ('cli' !== \PHP_SAPI) {
+    throw new Exception('This script must be run from the command line.');
+}
+
+$operators = ['not', '!', 'or', '||', '&&', 'and', '|', '^', '&', '==', '===', '!=', '!==', '<', '>', '>=', '<=', 'not in', 'in', '..', '+', '-', '~', '*', '/', '%', 'contains', 'starts with', 'ends with', 'matches', '**'];
+$operators = array_combine($operators, array_map('strlen', $operators));
+arsort($operators);
+
+$regex = [];
+foreach ($operators as $operator => $length) {
+    // Collisions of character operators:
+    // - an operator that begins with a character must have a space or a parenthesis before or starting at the beginning of a string
+    // - an operator that ends with a character must be followed by a whitespace or a parenthesis
+    $regex[] =
+        (ctype_alpha($operator[0]) ? '(?<=^|[\s(])' : '')
+        .preg_quote($operator, '/')
+        .(ctype_alpha($operator[$length - 1]) ? '(?=[\s(])' : '');
+}
+
+echo '/'.implode('|', $regex).'/A';