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/TODO.md

@@ -0,0 +1,8 @@
+- experiment with http://docs.php.net/manual/en/book.ds.php to improve performance. It has polyfil
+- iterators in Stream
+- generate regex
+- look at https://github.com/jubianchi/ppc
+- separate StringStream and MBStringStream
+- benchmark stream methods individually
+- more generally, benchmarking at the lowest levels first
+- use try for backtracking?