fix: add round(double precision, integer) overload so ad-hoc queries work without ::numeric casts

infra/migrations/022_round_float_overload.sql

@@ -0,0 +1,8 @@
+-- Add a round(double precision, integer) overload so ad-hoc queries
+-- using round(some_float, 2) work without explicit ::numeric casts.
+-- PostgreSQL only provides round(numeric, integer) out of the box.
+
+CREATE OR REPLACE FUNCTION round(double precision, integer)
+RETURNS numeric AS $$
+  SELECT round($1::numeric, $2);
+$$ LANGUAGE sql IMMUTABLE STRICT;