refactor: executors and routers

* refactor: executors and routers

internal/error/input.go

@@ -3,6 +3,11 @@ package error
 func NewRaceUnknownError(arg ...any) error {
 	return newGenericError(ErrInputUnknownRace, arg...)
 }
+
+func NewUnknownRelationError(arg ...any) error {
+	return newGenericError(ErrInputUnknownRelation, arg...)
+}
+
 func NewSameRaceError(arg ...any) error {
 	return newGenericError(ErrInputSameRace, arg...)
 }