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/README.md

@@ -0,0 +1,36 @@
+Dotenv Component
+================
+
+Symfony Dotenv parses `.env` files to make environment variables stored in them
+accessible via `$_SERVER` or `$_ENV`.
+
+Getting Started
+---------------
+
+```
+$ composer require symfony/dotenv
+```
+
+```php
+use Symfony\Component\Dotenv\Dotenv;
+
+$dotenv = new Dotenv();
+$dotenv->load(__DIR__.'/.env');
+
+// you can also load several files
+$dotenv->load(__DIR__.'/.env', __DIR__.'/.env.dev');
+
+// overwrites existing env variables
+$dotenv->overload(__DIR__.'/.env');
+
+// loads .env, .env.local, and .env.$APP_ENV.local or .env.$APP_ENV
+$dotenv->loadEnv(__DIR__.'/.env');
+```
+
+Resources
+---------
+
+ * [Contributing](https://symfony.com/doc/current/contributing/index.html)
+ * [Report issues](https://github.com/symfony/symfony/issues) and
+   [send Pull Requests](https://github.com/symfony/symfony/pulls)
+   in the [main Symfony repository](https://github.com/symfony/symfony)