refactor(core): enhance SDK structure and documentation

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

tests/Feature/Utils/UuidTest.php

@@ -0,0 +1,37 @@
+<?php
+
+use Apoloz\AlfaBank\Utils\Uuid;
+use Apoloz\AlfaBank\Http\Middleware\RequestIdMiddleware;
+use Saloon\Http\PendingRequest;
+use Saloon\Http\Request;
+use Saloon\Enums\Method;
+
+test('it generates valid uuid v4', function () {
+    $uuid = Uuid::v4();
+    
+    expect($uuid)->toBeString()
+        ->and(strlen($uuid))->toBe(36)
+        ->and(preg_match('/^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/', $uuid))->toBe(1);
+});
+
+test('middleware adds uuid to request', function () {
+    $middleware = new RequestIdMiddleware();
+    
+    $request = new class extends Request {
+        protected Method $method = Method::GET;
+        public function resolveEndpoint(): string { return '/'; }
+    };
+    
+    $connector = new class extends \Saloon\Http\Connector {
+        public function resolveBaseUrl(): string { return 'https://test'; }
+    };
+    
+    $pendingRequest = new PendingRequest($connector, $request);
+    
+    $middleware($pendingRequest);
+    
+    $header = $pendingRequest->headers()->get('X-Request-ID');
+    
+    expect($header)->toBeString()
+        ->and(preg_match('/^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/', $header))->toBe(1);
+});