- create MonitoringCheck schema for the monitoring_checks table, fixing
silent data loss where ping results were dropped by the wrong schema
- update agent channel and device monitor worker to use new schema
- fix Stats queries to use MonitoringCheck instead of Check schema
- add list_online_cloud_pollers and list_cloud_polled_devices queries
- add CloudLatencyProbeWorker to dispatch cross-agent latency probes
every 8 hours via PubSub to all online cloud pollers
- scope AgentLatencyEvaluator to cloud pollers only with cloud_only
filter, lower min_checks (5), wider time window (48h), and
device-level assignments to avoid changing site/org defaults
- update cron schedule: probes at 0/8/16h, evaluation at 0:30/8:30/16:30
- refactor monitoring.ex and http_executor.ex to fix credo complexity
Graham McIntire
a61abd836c