invite: add proto field (UDP/TCP/BOTH) to invite link binary format

Format per v4 addr: family(1) + socketId(1) + proto(1) + addr(4) + port(2) = 9 bytes (was 8)
Proto values: 0x01=UDP, 0x02=TCP, 0x03=BOTH
Affects: invite_link_c.h/c (Android), invite_link.h/cpp (desktop), chat_sync.c, conn_mgr.c, joindialog.cpp, utun_node.cpp

tools/chatgui/transport/utun_node.cpp

@@ -6,6 +6,7 @@
 #include "../../lib/socket_compat.h"
 
 #include "../db/db_manager.h"
+#include "../src/invite_link.h"
 
 // === C headers ===
 extern "C" {
@@ -157,6 +158,7 @@ QList<NodeAddr> UtunNode::getInviteAddresses(DbManager* db) {
                     if (link->link_state == 3 && link->nat_type == NAT_TYPE_DIRECT) {
                         NodeAddr a;
                         a.socketId = link->conn ? (int)link->conn->sock_id : 0;
+                        a.protocol = INVITE_PROTO_UDP;
                         struct sockaddr_storage* sa = &link->remote_addr;
                         if (sa->ss_family == AF_INET) {
                             struct sockaddr_in* sin = (struct sockaddr_in*)sa;
@@ -190,6 +192,7 @@ QList<NodeAddr> UtunNode::getInviteAddresses(DbManager* db) {
 
             NodeAddr a;
             a.socketId = (int)sock->sock_id;
+            a.protocol = INVITE_PROTO_UDP;
             if (sa->ss_family == AF_INET) {
                 struct sockaddr_in* sin = (struct sockaddr_in*)sa;
                 a.family = 4;