get_user_by_remnawave_uuid: fallback query searches Subscription table
when User-level UUID not found (multi-tariff stores UUID per-subscription).
Webhook _resolve_user_and_subscription: direct Subscription lookup before
returning None when user not found by telegram_id or User.remnawave_uuid.
Webhook user.deleted: refresh user.subscriptions before iterating to
ensure relationship is loaded from DB.
Account merge: clear subscription-level remnawave_uuid/short_uuid on
secondary user's subscriptions to prevent orphaned panel users.
c0mrade
c3c2b8137b