Tests: use code interface for Member create/update (actor propagation)

test/membership/member_cycle_calculations_test.exs

@@ -38,10 +38,8 @@ defmodule Mv.Membership.MemberCycleCalculationsTest do
     }
 
     attrs = Map.merge(default_attrs, attrs)
-
-    Member
-    |> Ash.Changeset.for_create(:create_member, attrs)
-    |> Ash.create!(actor: actor)
+    {:ok, member} = Mv.Membership.create_member(attrs, actor: actor)
+    member
   end
 
   # Helper to create a cycle