Member/Setting/validations: domain, actor, and seeds

- setting.ex: domain/authorize for default_membership_fee_type_id check
- validate_same_interval: require membership_fee_type (no None)
- set_membership_fee_start_date: domain/actor for fee type lookup
- Validations: domain/authorize for cross-resource checks
- helpers.ex, email_sync change, seeds.exs actor/authorize fixes
- Update related tests

lib/mv/email_sync/changes/sync_user_email_to_member.ex

@@ -27,6 +27,10 @@ defmodule Mv.EmailSync.Changes.SyncUserEmailToMember do
   Modified changeset with email synchronization applied, or original changeset
   if recursion detected.
   """
+  # Ash 3.12+ calls this to decide whether to run the change in certain contexts.
+  @impl true
+  def has_change?, do: true
+
   @impl true
   def change(changeset, _opts, context) do
     # Only recursion protection needed - trigger logic is in `where` clauses