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/JSON/StringLiteralTest.php

@@ -0,0 +1,61 @@
+<?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\JSON;
+
+use PHPUnit\Framework\TestCase;
+use Parsica\Parsica\JSON\JSON;
+use Parsica\Parsica\PHPUnit\ParserAssertions;
+
+final class StringLiteralTest extends TestCase
+{
+    use ParserAssertions;
+
+    public static function escapedChars(): array
+    {
+        return [
+            // label => [literal that will appear in json, expected character it results in]
+            "quotation mark" => ["\\\"", '"'],
+            "reverse solidus" => ['\\\\', '\\'],
+            "solidus" => ["\\/", '/'],
+            "backspace" => ["\\b", mb_chr(8)],
+            "formfeed" => ["\\f", mb_chr(12)],
+            "linefeed" => ["\\n", "\n"],
+            "carriage return" => ["\\r", "\r"],
+            "horizontal tab" => ["\\t", "\t"],
+        ];
+    }
+
+    /** @test */
+    public function empty()
+    {
+        $this->assertParses('""', JSON::stringLiteral(), "");
+    }
+
+    /**
+     * @test
+     * @dataProvider escapedChars
+     */
+    public function escapes(string $input, string $expected)
+    {
+        $this->assertParses('"' . $input . '"', JSON::stringLiteral(), $expected);
+        $this->assertParses('"a' . $input . '"', JSON::stringLiteral(), "a" . $expected);
+        $this->assertParses('"' . $input . 'a"', JSON::stringLiteral(), $expected . "a");
+    }
+
+    /** @test */
+    public function escape_hex()
+    {
+        $input = '"\\u0BB9\\u0BB2\\u0BCB\\u0020\\u0B89\\u0BB2\\u0B95\\u0BAE\\u0BCD"';
+        $this->assertParses($input, JSON::stringLiteral(), "ஹலோ உலகம்");
+    }
+
+
+}