Not sure why you'd vibe-code a new VPN protocol, double ratchet or otherwise, when you can just take WireGuard and make a new transport for it.
WireGuard by itself is not a stealth VPN, but the things that make a VPN "stealthy" are all things you'd layer on top of a WireGuard design, not thread through the middle of it. A datagram-based protocol can run under any obscured transport.
We did this at Fly.io when we discovered that, for one reason or another, 5% of our users simply couldn't reliably use UDP. It was a one-day project to run it under WebSockets instead, and that was before coding agents.
Wireguard is both really useful and pretty frustrating as a user. As a developer it's amazing that you can do things like relay packets through a bouncer with authentication to get around NAT without ever having to think about the protocol level safety, as a user it's near impossible to configure without the confused "why are no packets working", and as you had here it just doesn't make it through a lot of restrictive networking conditions. I'd love some middle ground between wireguard and tailscale in terms of complexity, their clients have way too much stuff in them.
The parent is obviously just Claude making a fancy website and some sort of unreviewed networking protocol that's dressed up to look as if it's a real project. Github really needs to start showing commit cadence and repo birthdates.