Deploying the previous commit's fix live exposed a real bug: nodogsplash's
OpenWrt package postinst auto-enables and starts the service immediately
on install, using its stock default config — gatewayinterface=br-lan.
Since NoDogSplash only touches IPv4 iptables, this silently cut IPv4
(not IPv6) connectivity for anything on br-lan, including the admin
management box plugged into this router's LAN port, for the window
between install and our own configure step.
Split nodogsplash provisioning into install_and_stop() (runs first,
closes that window immediately) and configure() (runs after
wifi::provision_ssid has created br-tollgate, so gatewayinterface is
pointed at the isolated tollgate bridge instead of br-lan).
ssmithx
7439a1251c