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/tests/sideEffectsTest.php

@@ -0,0 +1,53 @@
+<?php declare(strict_types=1);
+/**
+ * This file is part of the Parsica library.
+ *
+ * Copyright (c) 2020 Mathias Verraes <mathias@verraes.net>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Tests\Parsica\Parsica;
+
+use PHPUnit\Framework\TestCase;
+use Parsica\Parsica\StringStream;
+use function Parsica\Parsica\char;
+use function Parsica\Parsica\emit;
+
+final class sideEffectsTest extends TestCase
+{
+    /** @test */
+    public function emit()
+    {
+        $cache = new Cache();
+        $addToCache = fn($output) => $cache->add($output, $output);
+
+        $parser = emit(char('a'), $addToCache);
+
+        $input = "a";
+        $parser->run(new StringStream($input));
+        $this->assertEquals("a", $cache->get('a'));
+
+        $input = "b";
+        $parser->run(new StringStream($input));
+        $this->assertNull($cache->get('b'));
+    }
+}
+
+class Cache
+{
+    private $items = [];
+
+    function add($key, $value)
+    {
+        $this->items[$key] = $value;
+    }
+
+    function get($key)
+    {
+        return array_key_exists($key, $this->items)
+            ? $this->items[$key]
+            : null;
+    }
+}