Replace import with import type.

src/lib/parameters.ts

 import rootParameterUnknown from "@leximpact/socio-fiscal-openfisca-json/editable_processed_parameters.json"
 import {
-  AmountUnit,
   improveParameter,
   ParameterClass,
-  RateUnit,
   scaleByInstantFromBrackets,
   ScaleType,
   Unit,
   ValueType,
   walkParameters,
   type AmountBracketAtInstant,
+  type AmountUnit,
   type BracketAtInstant,
   type LinearAverageRateScaleParameter,
   type MarginalAmountScaleParameter,
@@ -17,6 +16,7 @@ import {
   type NodeParameter,
   type Parameter,
   type RateBracketAtInstant,
+  type RateUnit,
   type Reference,
   type ScaleAtInstant,
   type ScaleParameter,