Sub-ticket of VENUS-34 venus classifier-parity follow-up: add referer-discriminator to tierForNotFound so genuine-bad-routes tier stricter (ayudarg already has it); venus currently OVER-escalates - phantoms classified error/alert=true. OPTIONAL low-pri polish, NOT a fix: two-sink EVO-21 already removes the phantom source so this only affects FUTURE real bad-route tiering. Defer per pm-venus scope decision (do not fold into EVO-21 push). · venus