If you just have LAN, WAN and the IPsec tunnel, then incoming from WAN to anywhere is already blocked (unless you have enabled something). So you want to also block traffic from LAN heading to IPsec.
On LAN, above the general "allow all on LAN", add:
a) pass rule, source any, destination IPsec address/s port 80
b) block rule, source any, destination IPsec address/s port all