refactor: move slow performance tests to extra test suite

test/mv_web/live/group_live/index_test.exs

@@ -114,6 +114,7 @@ defmodule MvWeb.GroupLive.IndexTest do
     end
   end
 
+  @moduletag :slow
   describe "performance" do
     test "page loads efficiently with many groups", %{conn: conn} do
       # Create multiple groups

test/mv_web/live/group_live/show_test.exs

@@ -219,6 +219,7 @@ defmodule MvWeb.GroupLive.ShowTest do
     end
   end
 
+  @moduletag :slow
   describe "performance" do
     test "member list is loaded efficiently (no N+1 queries)", %{conn: conn} do
       group = Fixtures.group_fixture()