Validate GODOXY_LOCAL_API_ADDR before starting the unauthenticated local
API. Loopback listeners still succeed by default; addresses that bind
all interfaces, unspecified IPs, LAN hosts, or non-loopback names need
GODOXY_LOCAL_API_ALLOW_NON_LOOPBACK=true.
When that opt-in is set and the host is not loopback, log a warning so
non-local exposure is obvious. Wire common.LocalAPIAllowNonLoopback from
LOCAL_API_ALLOW_NON_LOOPBACK and document it (with a risk note) in
.env.example.
Add TestValidateLocalAPIAddr for loopback, wildcard, LAN, and hostname
cases with the allow flag on and off.