feat: 新增卡状态检查轮询数据库迁移

tb_polling_config 新增 card_status_check_interval INT NULL
tb_iot_card 新增 last_card_status_check_at TIMESTAMPTZ NULL
含 IF NOT EXISTS 保证幂等，含完整回滚文件

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

migrations/000120_add_polling_card_status.down.sql

@@ -0,0 +1,5 @@
+ALTER TABLE tb_polling_config
+    DROP COLUMN IF EXISTS card_status_check_interval;
+
+ALTER TABLE tb_iot_card
+    DROP COLUMN IF EXISTS last_card_status_check_at;