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/parsica-php/parsica/README.md

@@ -0,0 +1,46 @@
+# Parsica
+
+
+[![Tests](https://github.com/parsica-php/parsica/actions/workflows/tests.yml/badge.svg)](https://github.com/parsica-php/parsica/actions/workflows/tests.yml)
+
+The easiest way to build robust parsers in PHP.
+
+```bash
+composer require parsica-php/parsica
+```
+
+Documentation & API: [parsica-php.github.io](https://parsica-php.github.io/)
+
+
+```php
+<?php
+$parser = between(char('{'), char('}'), atLeastOne(alphaChar()));
+$result = $parser->tryString("{Hello}");
+echo $result->output(); // Hello
+```
+
+## Quality
+
+The code is entirely built with Test-Driven Development, and type-checked with [Psalm](https://github.com/vimeo/psalm). It is likely bug-free or very close to it. It is suitable for complex parsing requirements, and could even be used to build a programming language.
+However, it might not be performant enough if you use it at a high scale. 
+
+
+## Project Maintenance & Support
+
+Regrettably, the maintainer of this library (@turanct) has passed away in December 2021 due to cancer. The original author @mathiasverraes is now the maintainer again, and is doing occasional minor updates. If you'd like to contribute to this library, or if you wish to use this library for a project and need consulting, contact Mathias via mathias at verraes net. PR and issues submissions may not be monitored.
+
+## Development
+
+After running `composer install`, run these to validate if everything is in working order:
+
+```
+composer run phpunit
+composer run psalm
+composer run uptodocs
+
+# or all of them:
+
+composer run test
+```
+
+As this library uses pure functional programming, it may be hard to wrap your head around if you're used to object-oriented or imperative styles. Our recommendation is to familiarize yourself with the basics of functional programming, for example by reading an intro to Haskell.