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/league/csv/autoload.php

@@ -0,0 +1,14 @@
+<?php
+
+require __DIR__ . '/src/functions_include.php';
+
+spl_autoload_register(static function (string $class): void {
+    if (!str_starts_with($class, 'League\Csv\\')) {
+        return;
+    }
+
+    $file = __DIR__ . '/src/' . str_replace('\\', '/', substr($class, 11)).'.php';
+    if (is_readable($file)) {
+        require $file;
+    }
+});