The connector-trusted trust mode is the dev-only escape hatch and
must require both -trust=connector-trusted *and*
-dev.connector_trusted_ack. The latter is intentionally awkward to
flip so an operator cannot disable catalog validation by accident.
Add unit tests covering: default ok, port range, missing filer
addresses, connector-trusted without ack rejected, connector-trusted
with ack accepted, unknown trust modes rejected, and that the error
message names the ack flag so the operator knows how to proceed.