feat: WeChat status + QR on Dashboard, proactive login notifier

- /api/wechat/status: real login detection via webhook log + docker logs
- /api/platform: wechat_bridge now returns login_ok, message, qr_url
- Platform tab: inline QR code with 5min expiry + refresh button
- wechat_qr_notifier.py: 40h session-age WeChat warning + XMPP logout alert
- agents_health_check.py: login_check via docker logs
- wechat_webhook.py: timeout 180→600s

config/agents.yaml

@@ -30,7 +30,7 @@ agents:
     provider: ocg-new
     services:
       - type: hermes_gateway
-        port: 8642
+        port: 8646
       - type: xmpp_bot
 
   - id: "agent-004"