fix: pass actor to CustomFieldLive.FormComponent for save

IndexComponent now passes actor to FormComponent; FormComponent uses
assigns[:actor] instead of current_actor(socket). Add test that submits
new custom field form on settings page.

test/mv_web/live/custom_field_live/deletion_test.exs

@@ -15,6 +15,7 @@ defmodule MvWeb.CustomFieldLive.DeletionTest do
   use MvWeb.ConnCase, async: true
 
   import Phoenix.LiveViewTest
+  require Ash.Query
 
   alias Mv.Membership.{CustomField, CustomFieldValue, Member}
 
@@ -230,6 +231,46 @@ defmodule MvWeb.CustomFieldLive.DeletionTest do
     end
   end
 
+  describe "create custom field" do
+    test "submitting new data field form creates custom field and shows success", %{conn: conn} do
+      {:ok, view, _html} = live(conn, ~p"/settings")
+
+      # Open "New Data Field" form
+      view
+      |> element("#custom-fields-component button", "New Data Field")
+      |> render_click()
+
+      # Form is visible; submit with valid data
+      form_params = %{
+        "custom_field" => %{
+          "name" => "Created via Form",
+          "value_type" => "string",
+          "description" => "",
+          "required" => "false",
+          "show_in_overview" => "true"
+        }
+      }
+
+      view
+      |> form("#custom-field-form-new-form", form_params)
+      |> render_submit()
+
+      # Success flash (FormComponent needs actor from parent; without it KeyError would occur)
+      assert render(view) =~ "successfully"
+
+      # Custom field was created in DB
+      system_actor = Mv.Helpers.SystemActor.get_system_actor()
+      search_name = "Created via Form"
+
+      [custom_field] =
+        Mv.Membership.CustomField
+        |> Ash.Query.filter(name == ^search_name)
+        |> Ash.read!(actor: system_actor)
+
+      assert custom_field.value_type == :string
+    end
+  end
+
   # Helper functions
   defp create_member do
     system_actor = Mv.Helpers.SystemActor.get_system_actor()