Tests: member required fields, setting, member field live, sync_contact

Add tests for required validation, update_single_member_field, form
required map. Add street/postal_code/city to sync_contact when Vereinfacht configured.

test/mv_web/member_live/form_error_handling_test.exs

@@ -74,6 +74,45 @@ defmodule MvWeb.MemberLive.FormErrorHandlingTest do
                html =~ "Please correct" or html =~ "Bitte korrigieren"
     end
 
+    @tag :ui
+    test "shows validation error when settings-required field is missing", %{conn: conn} do
+      {:ok, settings} = Mv.Membership.get_settings()
+
+      {:ok, _} =
+        Mv.Membership.update_single_member_field(settings,
+          field: "first_name",
+          show_in_overview: true,
+          required: true
+        )
+
+      conn = conn_with_oidc_user(conn)
+      {:ok, view, _html} = live(conn, "/members/new")
+
+      # Submit without first_name (required in settings)
+      form_data = %{
+        "member[last_name]" => "User",
+        "member[email]" => "newuser#{System.unique_integer([:positive])}@example.com"
+      }
+
+      html =
+        view
+        |> form("#member-form", form_data)
+        |> render_submit()
+
+      assert html =~ "error" or html =~ "Error" or html =~ "Fehler" or
+               html =~ "first_name" or html =~ "First name" or html =~ "can't be blank" or
+               html =~ "darf nicht leer sein"
+
+      # Reset settings
+      {:ok, settings} = Mv.Membership.get_settings()
+
+      Mv.Membership.update_single_member_field(settings,
+        field: "first_name",
+        show_in_overview: true,
+        required: false
+      )
+    end
+
     test "shows flash message when member update fails", %{conn: conn} do
       system_actor = Mv.Helpers.SystemActor.get_system_actor()