test: restore deleted tests with dynamic field visibility support

Adapts icon distribution test for dynamic fields, restores empty cell test

test/mv_web/components/sort_header_component_test.exs

@@ -149,6 +149,29 @@ defmodule MvWeb.Components.SortHeaderComponentTest do
       assert html_neutral =~ "hero-chevron-up-down"
       assert has_element?(view, "[data-testid='email'] .opacity-40")
     end
+
+    test "icon distribution shows exactly one active sort icon", %{conn: conn} do
+      conn = conn_with_oidc_user(conn)
+
+      # Test neutral state - only one field should have active sort icon
+      {:ok, _view, html_neutral} = live(conn, "/members")
+
+      # Count active icons (should be exactly 1 - ascending for default sort field)
+      up_count = html_neutral |> String.split("hero-chevron-up ") |> length() |> Kernel.-(1)
+      down_count = html_neutral |> String.split("hero-chevron-down ") |> length() |> Kernel.-(1)
+
+      assert up_count == 1, "Expected exactly 1 ascending icon, got #{up_count}"
+      assert down_count == 0, "Expected 0 descending icons, got #{down_count}"
+
+      # Test descending state
+      {:ok, _view, html_desc} = live(conn, "/members?sort_field=first_name&sort_order=desc")
+
+      up_count = html_desc |> String.split("hero-chevron-up ") |> length() |> Kernel.-(1)
+      down_count = html_desc |> String.split("hero-chevron-down ") |> length() |> Kernel.-(1)
+
+      assert up_count == 0, "Expected 0 ascending icons, got #{up_count}"
+      assert down_count == 1, "Expected exactly 1 descending icon, got #{down_count}"
+    end
   end
 
   describe "accessibility" do