-- Tables affected: qt_configurations
-- recovery.not-started: safe to re-run; ADD COLUMN IF NOT EXISTS
-- recovery.partial: ALTER TABLE qt_configurations DROP COLUMN server_model;
-- recovery.completed: no action needed
-- verify: server_model column missing | SELECT 1 FROM information_schema.COLUMNS WHERE table_schema=DATABASE() AND table_name='qt_configurations' AND column_name='server_model' HAVING COUNT(*)=0

ALTER TABLE qt_configurations
    ADD COLUMN IF NOT EXISTS server_model VARCHAR(100) NULL AFTER server_count;