Information Geometry — Fisher-Rao regime distance

Most regime monitors compare summaries; this lens compares DISTRIBUTIONS, on the manifold where distance is intrinsic. The closed form keeps it exact and fast, and the calm baseline is chosen by rule, not by narrative convenience.

How it reads

fr_from_calm path with the calibrated bands; transition for step shocks. Read jumps as regime drift; read the LEVEL only against the documented baseline rule.