refactor(core): enhance SDK structure and documentation

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

src/Data/SelfEmployed/AgreementPageRequestData.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace Apoloz\AlfaBank\Data\SelfEmployed;
+
+use Spatie\LaravelData\Data;
+
+class AgreementPageRequestData extends Data
+{
+    public function __construct(
+        public ?string $phone = null,
+        public ?array $activities = null, // array of strings (activity IDs)
+        public ?array $regions = null, // array of strings (OKTMO)
+        public ?string $returnUrl = null,
+    ) {}
+}