Tests: restore settings in on_exit to avoid leftover state

Setup + on_exit save/restore member_field_visibility and
member_field_required in member, setting, index_component and
form_error_handling tests.

test/mv_web/live/member_field_live/index_component_test.exs

@@ -84,6 +84,23 @@ defmodule MvWeb.MemberFieldLive.IndexComponentTest do
   end
 
   describe "required fields" do
+    setup do
+      {:ok, settings} = Membership.get_settings()
+      saved_visibility = settings.member_field_visibility || %{}
+      saved_required = settings.member_field_required || %{}
+
+      on_exit(fn ->
+        {:ok, s} = Membership.get_settings()
+
+        Membership.update_settings(s, %{
+          member_field_visibility: saved_visibility,
+          member_field_required: saved_required
+        })
+      end)
+
+      :ok
+    end
+
     test "marks email as required (always from settings)", %{conn: conn} do
       {:ok, _view, html} = live(conn, ~p"/settings")
 
@@ -107,15 +124,6 @@ defmodule MvWeb.MemberFieldLive.IndexComponentTest do
       # First name row should show Required (and Optional for others)
       assert html =~ "First name" or html =~ "first_name"
       assert html =~ "Required"
-
-      # Reset
-      {:ok, settings} = Membership.get_settings()
-
-      Membership.update_single_member_field(settings,
-        field: "first_name",
-        show_in_overview: true,
-        required: false
-      )
     end
 
     test "optional fields show Optional when not required in settings", %{conn: conn} do