Detect the language of a text with franc (pure-JS trigram model, 61 languages + CJK/Indic scripts). Returns the ISO 639-1 code (639-3 when no 2-letter code exists), language name, a separation-margin confidence (0=ambiguous, 1=unambiguous), a reliable flag, and ranked alternatives. The pre-sort step of any multilingual pipeline. Short/ambiguous text returns reliable:false honestly. Processes provided text only; nothing is fetched.