refactor(core): enhance SDK structure and documentation

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

tests/Feature/Utils/CryptoTest.php

@@ -0,0 +1,36 @@
+<?php
+
+use Apoloz\AlfaBank\Utils\CardEncryptor;
+use Apoloz\AlfaBank\Utils\CmsSigner;
+
+test('can encrypt card pan', function () {
+    // Generate a temporary RSA key for testing
+    $res = openssl_pkey_new([
+        "private_key_bits" => 2048,
+        "private_key_type" => OPENSSL_KEYTYPE_RSA,
+    ]);
+    openssl_pkey_export($res, $privateKey);
+    $details = openssl_pkey_get_details($res);
+    $publicKey = $details['key'];
+
+    $pan = '4779642610000010';
+    $encrypted = CardEncryptor::encrypt($pan, $publicKey);
+
+    expect($encrypted)->toBeString()
+        ->and(base64_decode($encrypted))->not->toBeFalse();
+});
+
+test('can canonicalize json', function () {
+    $data = [
+        'z' => 1,
+        'a' => [
+            'c' => 3,
+            'b' => 2
+        ]
+    ];
+
+    $canonical = CmsSigner::canonicalize($data);
+    
+    // Keys should be sorted: a (then b, c), z
+    expect($canonical)->toBe('{"a":{"b":2,"c":3},"z":1}');
+});