uasync: replace raw socket_node* handle with packed index — fixes UAF after socket_array realloc
tcp_io: defer u_free in tcp_conn_destroy via uasync_call_soon — prevents callback-chain UAF
tcp_io: guard read_cb/write_cb with NULL queue checks after deferred destroy
tcp_io: save read_queue to local before queue_data_put + NULL guard after
route_connectivity: linked-list probe_ctx — cancel all parallel probes before nq free
- 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
Evgeny