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/src/joindialog.cpp

@@ -179,6 +179,7 @@ void JoinDialog::onConnectClicked() {
     for (const auto& a : d.addrs) {
         addrsBuf.append(static_cast<char>(a.family));
         addrsBuf.append(static_cast<char>(a.socketId));
+        addrsBuf.append(static_cast<char>(a.proto));
         addrsBuf.append(a.address);
         addrsBuf.append(static_cast<char>((a.port >> 8) & 0xFF));
         addrsBuf.append(static_cast<char>(a.port & 0xFF));