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/sebastian/lines-of-code/README.md

@@ -0,0 +1,22 @@
+# sebastian/lines-of-code
+
+Library for counting the lines of code in PHP source code.
+
+[![Latest Stable Version](https://img.shields.io/packagist/v/sebastian/lines-of-code.svg?style=flat-square)](https://packagist.org/packages/sebastian/lines-of-code)
+[![Minimum PHP Version](https://img.shields.io/badge/php-%3E%3D%207.3-8892BF.svg?style=flat-square)](https://php.net/)
+[![CI Status](https://github.com/sebastianbergmann/lines-of-code/workflows/CI/badge.svg?branch=master&event=push)](https://phpunit.de/build-status.html)
+[![Type Coverage](https://shepherd.dev/github/sebastianbergmann/lines-of-code/coverage.svg)](https://shepherd.dev/github/sebastianbergmann/lines-of-code)
+
+## Installation
+
+You can add this library as a local, per-project dependency to your project using [Composer](https://getcomposer.org/):
+
+```
+composer require sebastian/lines-of-code
+```
+
+If you only need this library during development, for instance to run your project's test suite, then you should add it as a development-time dependency:
+
+```
+composer require --dev sebastian/lines-of-code
+```