feat(vereinfacht): Settings UI and bulk sync

- GlobalSettingsLive: Vereinfacht section, sync button, last sync result
- Test: Vereinfacht Integration section visible

test/mv_web/live/global_settings_live_config_test.exs

@@ -71,4 +71,18 @@ defmodule MvWeb.GlobalSettingsLiveConfigTest do
       end
     end
   end
+
+  describe "Vereinfacht Integration section" do
+    setup %{conn: conn} do
+      admin_user = Mv.Fixtures.user_with_role_fixture("admin")
+      conn = MvWeb.ConnCase.conn_with_password_user(conn, admin_user)
+      {:ok, conn: conn}
+    end
+
+    @tag :ui
+    test "settings page shows Vereinfacht Integration section", %{conn: conn} do
+      {:ok, _view, html} = live(conn, ~p"/settings")
+      assert html =~ "Vereinfacht"
+    end
+  end
 end