Add WeBuy license validation and usage logging API endpoints

- Add /api/license/webuy/ endpoint for license validation
- Add /api/license/webuy/log/ endpoint for usage logging
- Logs stored in /var/www/logs/webuy_usage.log

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

api/license/webuy/index.php

@@ -0,0 +1,13 @@
+<?php
+header('Content-Type: text/plain');
+
+// Simple validation - customize to your needs
+// Options: hardcoded, database lookup, check against allowed machine IDs, etc.
+
+$valid = true; // Replace with your validation logic
+
+if ($valid) {
+    echo 'valid';
+} else {
+    echo 'License expired or invalid.';
+}