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/phpunit/php-code-coverage/README.md

@@ -0,0 +1,48 @@
+# phpunit/php-code-coverage
+
+[![Latest Stable Version](https://poser.pugx.org/phpunit/php-code-coverage/v/stable.png)](https://packagist.org/packages/phpunit/php-code-coverage)
+[![CI Status](https://github.com/sebastianbergmann/php-code-coverage/workflows/CI/badge.svg)](https://github.com/sebastianbergmann/php-code-coverage/actions)
+[![Type Coverage](https://shepherd.dev/github/sebastianbergmann/php-code-coverage/coverage.svg)](https://shepherd.dev/github/sebastianbergmann/php-code-coverage)
+
+Provides collection, processing, and rendering functionality for PHP code coverage information.
+
+## Installation
+
+You can add this library as a local, per-project dependency to your project using [Composer](https://getcomposer.org/):
+
+```
+composer require phpunit/php-code-coverage
+```
+
+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 phpunit/php-code-coverage
+```
+
+## Usage
+
+```php
+<?php declare(strict_types=1);
+use SebastianBergmann\CodeCoverage\Filter;
+use SebastianBergmann\CodeCoverage\Driver\Selector;
+use SebastianBergmann\CodeCoverage\CodeCoverage;
+use SebastianBergmann\CodeCoverage\Report\Html\Facade as HtmlReport;
+
+$filter = new Filter;
+$filter->includeDirectory('/path/to/directory');
+
+$coverage = new CodeCoverage(
+    (new Selector)->forLineCoverage($filter),
+    $filter
+);
+
+$coverage->start('<name of test>');
+
+// ...
+
+$coverage->stop();
+
+
+(new HtmlReport)->process($coverage, '/tmp/code-coverage-report');
+```