- remove sock_transport, transport abstraction, active connections API
- simplify proxy_conn to 13 fields (was 15), remove tcp_proxy_mapping linked list
- new protocol: stream_id 4B, seq 2B cyclic, HDR_SIZE 8B
- add ERROR subcmd for immediate abort, CLOSE for graceful half-close
- proper half-close: shutdown SHUT_WR, keep reading, no timer
- exhaustive DEBUG_ERROR/WARN on all error/unusual branches
- config parser: report unknown options with filename:line and valid keys
- proxy_uip_retry_cb: retry send from uip_to_transport every 5ms
- proxy_recv_cb: buffer to uip_to_transport when send fails, set retry timer
- proxy_feed: drain transport_to_uip when closing_tun || closing_sent (prevents RST)
- proxy_recv_cb(p==NULL): only tcp_recved + closing_tun, no drain
- proxy_poll_cb/tcp_proxy_destroy: cancel retry timer on cleanup
- uip_retry_timer field in proxy_conn
- Add closing_sent flag to proxy_conn (CLOSE sent to exit, no need to wait for reply)
- proxy_poll_cb: send CLOSE when done || sndbuf==0; cleanup when tun && (rem||sent)
- Destroy transport in proxy_poll_cb cleanup (fix 56-byte leak)
- remote_proxy_handle_close: shutdown(SHUT_WR) + 2s timer instead of immediate rp_conn_free
- Remove SHUTDOWN subcommand entirely (not needed with new lifecycle)
- UDP proxy: datagram relay client↔exit over ETCP
- ICMP proxy: echo ping relay client↔exit over ETCP
- Move via_node_id from per-forward-mapping to global tcp_proxy setting
- Support multiple concurrent tcp_proxy instances (no singleton g_tcp_proxy)
- Cap handshake padding to stay within 1472+overhead
- Handle non-TCP packets (UDP/ICMP) in tcp_proxy raw/tun input paths
- Add utun_instance_create_from_str() for test config creation
etcp_router: routable service packets with dst/src node_id
- etcp_router_bind/unbind: per-instance service handler registry
- etcp_route_send: send to node by id via BGP routing
- multi-hop forwarding through intermediate nodes
- loopback optimization (dst==self dispatches directly)
remote_proxy: exit node creating OS sockets on demand
- handles CONNECT/DATA/CLOSE via etcp_router
- non-blocking socket connect with uasync callbacks
- echo back response data to requesting node
tcp_proxy: etcp_transport for remote proxy
- via_node_id in mapping selects between sock/etcp transport
- unified handler for both tcp_proxy and remote_proxy roles
- config: forward = port -> ip:port via NODE_HEX [remote_proxy] section
tests: test_etcp_router (20 pkts bidirectional), test_remote_proxy (echo)
Evgeny