Fix missing max_errors assign in GlobalSettingsLive

Set max_errors as socket assign in mount/3 to make it
available in templates. Fixes KeyError in CSV import UI.

lib/mv_web/live/global_settings_live.ex

@@ -75,6 +75,7 @@ defmodule MvWeb.GlobalSettingsLive do
       |> assign(:import_progress, nil)
       |> assign(:import_status, :idle)
       |> assign(:locale, locale)
+      |> assign(:max_errors, @max_errors)
       |> assign_form()
       # Configure file upload with auto-upload enabled
       # Files are uploaded automatically when selected, no need for manual trigger