Tightens the bridge-trust check so a connection on the Docker bridge
is only granted local-operator status when its source IP matches a
configured frontend container hostname (default: `frontend` + the
shipped `container_name` `shadowbroker-frontend`). Previously, when
`SHADOWBROKER_TRUST_DOCKER_BRIDGE_LOCAL_OPERATOR=1` was set, ANY IP
in the 172.16.0.0/12 range was granted local-operator privileges —
on a shared Docker host that included any unrelated container on the
same bridge.
Operators with renamed services can list new hostnames via the new
`SHADOWBROKER_TRUSTED_FRONTEND_HOSTS` env var (comma-separated). DNS
resolution is cached for 30s; if Docker DNS can't resolve any of the
configured names we fail closed and refuse the bridge entirely.
Single-user installs see no behavior change — the default-named
frontend container still resolves and is still trusted.
Credit: tg12 (external security audit)
Shadowbroker