Release v0.7.0 - Security Hardening

Security Fixes:
- Fixed XSS vulnerability in checkout blocks DOM injection (replaced innerHTML with safe DOM methods)
- Unified IP detection for rate limiting across all API endpoints (new IpDetectionTrait)
- Added rate limiting to license transfers (5/hour) and downloads (30/hour) (new RateLimitTrait)
- Added file size limit (2MB), row limit (1000), and rate limiting to CSV import
- Added JSON decode error handling in StoreApiExtension
- Added license ID validation in frontend.js to prevent selector injection

New Files:
- src/Api/IpDetectionTrait.php - Shared IP detection with proxy support
- src/Common/RateLimitTrait.php - Reusable rate limiting for frontend operations

Breaking Changes:
- None

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

src/Frontend/DownloadController.php

@@ -9,6 +9,7 @@ declare(strict_types=1);
 
 namespace Jeremias\WcLicensedProduct\Frontend;
 
+use Jeremias\WcLicensedProduct\Common\RateLimitTrait;
 use Jeremias\WcLicensedProduct\License\LicenseManager;
 use Jeremias\WcLicensedProduct\Product\VersionManager;
 
@@ -17,6 +18,8 @@ use Jeremias\WcLicensedProduct\Product\VersionManager;
  */
 final class DownloadController
 {
+    use RateLimitTrait;
+
     private LicenseManager $licenseManager;
     private VersionManager $versionManager;
 
@@ -110,6 +113,15 @@ final class DownloadController
             exit;
         }
 
+        // Rate limit: 30 downloads per hour per user
+        if (!$this->checkUserRateLimit('download', 30, 3600)) {
+            wp_die(
+                __('Too many download attempts. Please try again later.', 'wc-licensed-product'),
+                __('Download Error', 'wc-licensed-product'),
+                ['response' => 429]
+            );
+        }
+
         // Get license
         $license = $this->licenseManager->getLicenseById($licenseId);
         if (!$license) {