Carmentalia: Prophecy at the Threshold   Carmentalia is not a loud festival. It does not celebrate conquest, fertility, or spectacle. It honors Carmenta, an ancient Roman prophetic goddess whose power lives in thresholds, language, and the perilous moment when the future becomes speakable.   Observed traditionally on January 11 and January 15, Carmentalia occupies a liminal pocket in the Roman calendar. The year has begun, but it has not yet hardened. Fate remains grammatical