-- 设备发现只形成候选事实；操作员保存后才进入正式检测柜列表。
ALTER TABLE t_detection_cabinet
    ADD COLUMN registration_status VARCHAR(16) NOT NULL DEFAULT 'DISCOVERED'
        COMMENT 'DISCOVERED发现候选，REGISTERED已登记' AFTER last_seen_at_utc,
    ADD CONSTRAINT chk_cabinet_registration_status
        CHECK (registration_status IN ('DISCOVERED', 'REGISTERED')),
    ADD KEY idx_cabinet_registration (registration_status, del_flag, last_seen_at_utc);