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/phpdocumentor/graphviz/README.md

@@ -0,0 +1,27 @@
+[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
+[![Travis Status](https://img.shields.io/travis/phpDocumentor/GraphViz.svg?label=Linux)](https://travis-ci.org/phpDocumentor/GraphViz)
+[![Appveyor Status](https://img.shields.io/appveyor/ci/phpDocumentor/GraphViz.svg?label=Windows)](https://ci.appveyor.com/project/phpDocumentor/GraphViz/branch/master)
+[![Coveralls Coverage](https://img.shields.io/coveralls/github/phpDocumentor/GraphViz.svg)](https://coveralls.io/github/phpDocumentor/GraphViz?branch=master)
+[![Scrutinizer Code Coverage](https://img.shields.io/scrutinizer/coverage/g/phpDocumentor/GraphViz.svg)](https://scrutinizer-ci.com/g/phpDocumentor/GraphViz/?branch=master)
+[![Scrutinizer Code Quality](https://img.shields.io/scrutinizer/g/phpDocumentor/GraphViz.svg)](https://scrutinizer-ci.com/g/phpDocumentor/GraphViz/?branch=master)
+[![Stable Version](https://img.shields.io/packagist/v/phpDocumentor/GraphViz.svg)](https://packagist.org/packages/phpDocumentor/GraphViz)
+[![Unstable Version](https://img.shields.io/packagist/vpre/phpDocumentor/GraphViz.svg)](https://packagist.org/packages/phpDocumentor/GraphViz)
+
+
+GraphViz
+========
+
+GraphViz is a library meant for generating .dot files for GraphViz with a
+fluent interface.
+
+
+### PHPStan extension
+
+This library contains a number of magic methods to set attributes on `Node`, `Graph` and `Edge`
+this will result in errors when using the library with checks by PHPStan. For your convenience this
+library provides an phpStan extension so your code can be checked correctly by phpstan.
+
+```
+includes:
+    - vendor/phpdocumentor/graphviz/extension.neon
+```