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/reflection/docs/extending/index.rst

@@ -0,0 +1,34 @@
+.. _extending:
+
+Extend the library
+==================
+
+The model exposed by this library is closed for inheritance. We did this to ensure the model is stable and does not
+change via external factors. The complexity of this project makes it hard to keep all the internal classes stable.
+The model is designed to be cached and constructed very carefully to ensure performance and memory usage are optimal.
+
+Metadata
+--------
+
+Metadata is a way to extend the model with additional information. We call this metadata, as all first class
+elements in the reflected codebase are part of the model. Extra data can be added to these elements using metadata.
+
+Elements supporting metadata are:
+
+.. phpdoc:class-list:: [?(@.interfaces contains "\phpDocumentor\Reflection\Metadata\MetaDataContainer")]
+
+   .. phpdoc:name::
+
+.. warning::
+
+    Adding metadata might break the posibilty to cache the model. Be carefull with circular references and large
+    objects. We do recommend to keep the metadata small and simple.
+
+Continue reading :doc:`Creating your first metadata <meta-data>`_ to learn how to create your own metadata.
+
+.. toctree::
+   :maxdepth: 1
+   :titlesonly:
+   :hidden:
+
+   meta-data