5e63a70215
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