pub fn warn_once(reason: &str)Expand description
Print reason to stderr ONCE per distinct reason string, for the
lifetime of this process — the “loud, one-time persistent warning” the
build brief calls for on an escalation = "allow"/approved-ask run,
and on a network gap. Deduped by exact text (not a blanket
once-per-process Once) so a DIFFERENT gap later in the same run still
gets its own warning — only an EXACT repeat is suppressed.