Add GATEWAY_IP, GATEWAY_PREFIX, GATEWAY_NETWORK, DHCP_RANGE_START, and
DHCP_RANGE_END variables to deploy.conf. Update ap/21-van-br0.network,
ap/van-ap-dnsmasq.conf, and ap/nftables.conf to use @TOKEN@ placeholders
for IP configuration instead of hardcoding 10.42.x addresses.
This allows deploying the same configuration to multiple routers on
different networks (e.g., Pi 5 on 10.42.0.x and R5C on 10.42.1.x) by
simply editing deploy.conf before running ./deploy.sh.
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>