Receive keepalive through the owning ETCP link, preserve RX deadlines, and report routing metrics without TUN. Use independent netlink requests and track installed routes for rollback. Reject incomplete resource initialization and release partially constructed cores while preserving caller config ownership.
Validated startup failure and rollback, padded keepalive, standby, STCP traffic, transport lifecycle, dynamic sockets, and daemon startup. Real TUN/netlink checks passed in an isolated Linux network namespace; modified modules passed FreeBSD compilation checks.
- u_async.c: process immediate_queue BEFORE epoll_wait in uasync_poll
- stcp_link.c: defensive NULL etcp_conn/etcp_link in stcp_link_close
- utun_instance.c: move stcp_server_list_destroy_all to Phase J (before ETCP),
add deferred drain in both Phase J and L
- stcp.h/c: STCP_HS_ENC_CLIENT 6→38, STCP_HS_ENC_SERVER 7→39,
exchange ed25519_pubkey in both handshake directions
- etcp_connections.c: copy peer_ed25519 from STCP to ETCP_CONN in
etcp_link_enter_ready_tcp; guard link->etcp in tcp_link_close_cb
- chat_sync.c: fix lk->conn NULL dereference for TCP links
- test_stcp.c: update stcp_server_create/stcp_client_connect callsites
- tools/chat_tcp_test: change transport udp→tcp
evgeny