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/dotenv/Exception/FormatException.php

@@ -0,0 +1,34 @@
+<?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\Dotenv\Exception;
+
+/**
+ * Thrown when a file has a syntax error.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+final class FormatException extends \LogicException implements ExceptionInterface
+{
+    private FormatExceptionContext $context;
+
+    public function __construct(string $message, FormatExceptionContext $context, int $code = 0, ?\Throwable $previous = null)
+    {
+        $this->context = $context;
+
+        parent::__construct(\sprintf("%s in \"%s\" at line %d.\n%s", $message, $context->getPath(), $context->getLineno(), $context->getDetails()), $code, $previous);
+    }
+
+    public function getContext(): FormatExceptionContext
+    {
+        return $this->context;
+    }
+}