Reconcile internal stateless documentation

docs/internal/forecast-derivation.md

@@ -46,9 +46,7 @@ UTC when these APIs are called directly. Optional narrative, discussion, and
 alerts remain absent when their normalized products are absent.
 
 Forecast thresholds used for brief indicators and precipitation timing are
-implementation rules. User-configurable Recent Changes thresholds are applied
-by [changes internals](changes.md), whose defaults are documented in
-[configuration](../config.md).
+implementation rules.
 
 ## Verification and invariants