Add object-oriented license client library (v0.0.2)

- Add LicenseClient with PSR-3 logging and PSR-6 caching support
- Add DTO classes: LicenseInfo, LicenseStatus, ActivationResult
- Add LicenseState enum for license status values
- Add comprehensive exception hierarchy for error handling
- Add PSR dependencies (psr/log, psr/cache, psr/http-client)
- Update README with usage examples
- Update CHANGELOG for v0.0.2

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/Dto/ActivationResult.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Magdev\WcLicensedProductClient\Dto;
+
+final readonly class ActivationResult
+{
+    public function __construct(
+        public bool $success,
+        public string $message,
+    ) {
+    }
+
+    public static function fromArray(array $data): self
+    {
+        return new self(
+            success: $data['success'],
+            message: $data['message'],
+        );
+    }
+}