monero: check every five minutes again

The probes, the unit check and the public checks ran once a day with 26h
windows, justified as "a multi-week initial sync on a rotating disk". That
stopped being true: the node is synced, and a cold explorer page now renders
in 29s and a warm one in 0.2s - polling every 5 minutes is what keeps it warm.
A dead monerod could go unnoticed for a day.

Back to the standard 5m cadence and 11m heartbeat; the per-host
service_health override on monerod-box is gone.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

ansible/infra/401_service_monitoring.yml

@@ -99,9 +99,9 @@
         healthcheck_units: "{{ monitored_services }}"
         healthcheck_units_key_prefix: "services_{{ host_key }}"
         # Cadence and heartbeat window are ONE decision, and both are a property
-        # of the host - monerod-box runs a multi-week sync nobody needs polled
-        # every five minutes, so it declares a daily schedule in its host_vars
-        # and a matching window above. Everything else keeps 5min/11m.
+        # of the host: a host can set service_health_on_calendar and a matching
+        # service_health_heartbeat in its host_vars. None does today; everything
+        # runs 5min/11m. (monerod-box was daily during its initial sync.)
         #
         # An empty healthcheck_on_calendar means "use healthcheck_interval" -
         # see the timer template in roles/healthcheck.