refactor: Use submit_form wrapper in all LiveView forms

- Replace AshPhoenix.Form.submit with submit_form/3 wrapper
- Import current_actor and submit_form from LiveHelpers
- Consistent actor handling in all form submissions

lib/mv_web/live/custom_field_live/form_component.ex

@@ -91,7 +91,9 @@ defmodule MvWeb.CustomFieldLive.FormComponent do
 
   @impl true
   def handle_event("save", %{"custom_field" => custom_field_params}, socket) do
-    case AshPhoenix.Form.submit(socket.assigns.form, params: custom_field_params) do
+    actor = MvWeb.LiveHelpers.current_actor(socket)
+
+    case MvWeb.LiveHelpers.submit_form(socket.assigns.form, custom_field_params, actor) do
       {:ok, custom_field} ->
         action =
           case socket.assigns.form.source.type do