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/console/Formatter/NullOutputFormatter.php

@@ -0,0 +1,51 @@
+<?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\Console\Formatter;
+
+/**
+ * @author Tien Xuan Vo <tien.xuan.vo@gmail.com>
+ */
+final class NullOutputFormatter implements OutputFormatterInterface
+{
+    private NullOutputFormatterStyle $style;
+
+    public function format(?string $message): ?string
+    {
+        return null;
+    }
+
+    public function getStyle(string $name): OutputFormatterStyleInterface
+    {
+        // to comply with the interface we must return a OutputFormatterStyleInterface
+        return $this->style ??= new NullOutputFormatterStyle();
+    }
+
+    public function hasStyle(string $name): bool
+    {
+        return false;
+    }
+
+    public function isDecorated(): bool
+    {
+        return false;
+    }
+
+    public function setDecorated(bool $decorated): void
+    {
+        // do nothing
+    }
+
+    public function setStyle(string $name, OutputFormatterStyleInterface $style): void
+    {
+        // do nothing
+    }
+}