Replace victoriametrics with influxdb in Varys service checks

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

config.yaml

@@ -36,6 +36,14 @@ services:
     url: http://172.27.40.3:7575
   - name: netbox
     url: http://172.27.40.3:8100
+  - name: netbird-dashboard
+    url: http://netbird-dashboard:80
+  - name: netbird-server
+    url: http://netbird-server:80
+  - name: influxdb
+    url: http://influxdb:8086/health
+  - name: grafana
+    url: http://grafana:3000/api/health
 
 # One-shot agents to watchdog (reads /opt/agent-os/logs/<name>/last-run.json).
 agents: