* Adds management, signal, and relay (STUN/TURN) health probes to the status command.
* Adds a reason when the management or signal connections are disconnected.
* Adds last wireguard handshake and received/sent bytes per peer
Add netstack support for the agent to run it without privileges.
- use interface for tun device
- use common IPC for userspace WireGuard integration
- move udpmux creation and sharedsock to tun layer