feat: XRay Reality key backup and restoration

- Modified migrations/048_enable_xray_stats.sql to accept existing keys via env vars (PRIVATE_KEY, SHORT_ID)
- Updated InstallProtocolManager.php to extract and store reality_private_key after XRay installation
- Added key restoration logic in buildExports() to reuse saved keys during reinstallation
- Fixed VpnClient.php to correctly parse JSON stats output from XRay API
- Security fix: removed exposed port 2375 from docker-compose.yml (dind container)

docker-compose.yml

@@ -57,8 +57,7 @@ services:
     restart: unless-stopped
     environment:
       DOCKER_TLS_CERTDIR: ""
-    ports:
-      - "2375:2375"
+
     volumes:
       - dind_data:/var/lib/docker