feat: PING/PONG RTT exchange + burst sender + TCP server; fix INIT peer_id offset

- etcp_connections: add flags byte to PING/PONG wire format (WANT_RTT/SEND_RTT)
- etcp_connections: add etcp_link_burst_start/check for BDP measurement
- etcp_connections: add tcp_server_on_link for STCP→ETCP bridge
- topo_node: add ping_request_cbk/ping_update_rtt for live RTT tracking
- topo_node: add last_ping_time field in connectivity
- topo_node_sqlite: extend DB schema for RTT data
- fix: INIT path read peer_id from offset 1 (not 2), PING offset stays 2

src/routing_layer/topo_node_sqlite.h

@@ -49,4 +49,7 @@ int topo_node_sqlite_node_set_online(sqlite3* db, uint64_t node_id, int online);
 int topo_node_sqlite_node_get_online(sqlite3* db, uint64_t node_id);
 int topo_node_sqlite_get_ed25519_pubkey(sqlite3* db, uint64_t node_id, uint8_t pubkey_out[32]);
 
+/** Пересчитывает node_type во всех peers_* таблицах на основе addr_type из node_addresses */
+int topo_node_sqlite_nodeinfo_updated(sqlite3* db, uint64_t node_id);
+
 #endif