Replaces DIY natpmpc sidecar with gluetun's built-in NAT-PMP handling for the protonvpn
provider. The natpmpc UDP response was being dropped by gluetun's firewall since conntrack
doesn't track stateless UDP from the gateway. With VPN_PORT_FORWARDING=on, gluetun handles
the NAT-PMP exchange internally and exposes the port at :8000/v1/openvpn/portforwarded.
Helper sidecar now just polls that endpoint.
Two initial Fornax distributed torrent workers, each a gluetun+qBittorrent+natpmpc-helper
pod on a different ProtonVPN TX server with NAT-PMP enabled. VPN private keys stored in
Vault at secret/fornax/worker-tx253 and secret/fornax/worker-tx34, surfaced via
ExternalSecrets. Workers share the media-data PVC; each has its own config PVC.
Services: fornax-worker-tx253:8080 and fornax-worker-tx34:8080 (ClusterIP, media ns)
Will Anderson