系统设置增加中控企业微信告警，后台巡检离线/故障并冷却推送。

Co-authored-by: Cursor <cursoragent@cursor.com>

.env.example

@@ -1,9 +1,15 @@
-# crypto_okx_hub
-APP_HOST=0.0.0.0
-APP_PORT=5100
-HUB_USERNAME=admin
-HUB_PASSWORD=admin123
-FLASK_SECRET_KEY=change-me-to-long-random
-DB_PATH=hub.db
-HUB_PULL_INTERVAL_SEC=10
-HUB_PULL_TIMEOUT_SEC=5
+# crypto_okx_hub
+APP_HOST=0.0.0.0
+APP_PORT=5100
+HUB_USERNAME=admin
+HUB_PASSWORD=admin123
+FLASK_SECRET_KEY=change-me-to-long-random
+DB_PATH=hub.db
+HUB_PULL_INTERVAL_SEC=10
+HUB_PULL_TIMEOUT_SEC=5
+
+# 中控企业微信(离线/故障告警,与客户端通知分开)
+HUB_WECHAT_ENABLED=false
+HUB_WECHAT_WEBHOOK=
+HUB_ALERT_COOLDOWN_SEC=600
+HUB_HEALTH_FAIL_THRESHOLD=2