Introduces mixtcp, a smoltcp-based device that tunnels TCP/IP through
the mixnet via IpMixStream and Exit Gateway IPRs.
Components:
- NymIprDevice: smoltcp::phy::Device impl using channel-based I/O
- NymIprBridge: async task bridging the device to IpMixStream
- create_device(): helper to set up the complete stack
Examples:
- cloudflare_ping: ICMP ping through the mixnet
- https_client: HTTPS requests through the mixnet
- tls: TLS connections through the mixnet
mfahampshire