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/README.md

@@ -0,0 +1,19 @@
+Symfony PSR-6 implementation for caching
+========================================
+
+The Cache component provides extended
+[PSR-6](https://www.php-fig.org/psr/psr-6/) implementations for adding cache to
+your applications. It is designed to have a low overhead so that caching is
+fastest. It ships with adapters for the most widespread caching backends.
+It also provides a [PSR-16](https://www.php-fig.org/psr/psr-16/) adapter,
+and implementations for [symfony/cache-contracts](https://github.com/symfony/cache-contracts)'
+`CacheInterface` and `TagAwareCacheInterface`.
+
+Resources
+---------
+
+ * [Documentation](https://symfony.com/doc/current/components/cache.html)
+ * [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)