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/cache/Marshaller/DeflateMarshaller.php

@@ -0,0 +1,47 @@
+<?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\Cache\Marshaller;
+
+use Symfony\Component\Cache\Exception\CacheException;
+
+/**
+ * Compresses values using gzdeflate().
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+class DeflateMarshaller implements MarshallerInterface
+{
+    private MarshallerInterface $marshaller;
+
+    public function __construct(MarshallerInterface $marshaller)
+    {
+        if (!\function_exists('gzdeflate')) {
+            throw new CacheException('The "zlib" PHP extension is not loaded.');
+        }
+
+        $this->marshaller = $marshaller;
+    }
+
+    public function marshall(array $values, ?array &$failed): array
+    {
+        return array_map('gzdeflate', $this->marshaller->marshall($values, $failed));
+    }
+
+    public function unmarshall(string $value): mixed
+    {
+        if (false !== $inflatedValue = @gzinflate($value)) {
+            $value = $inflatedValue;
+        }
+
+        return $this->marshaller->unmarshall($value);
+    }
+}