status alerts grace period 10 mins

README.md

@@ -825,7 +825,7 @@ full-size PNG when a graph is clicked.
 
 The collector also sends an ntfy notification when:
 
-- The UPS status changes
+- The UPS status changes and the new status persists for 10 minutes
 - Mean battery charge over the last 10 measurements crosses below 50%
 - Mean battery charge over the last 10 measurements crosses below 5%
 - Estimated battery runtime crosses below 5 minutes
@@ -835,6 +835,12 @@ Alert state is stored in `/var/lib/rrd/bx950mi-alert-state.json`, allowing
 changes to be detected across cron runs. The first run establishes a baseline
 without sending notifications. Threshold notifications can fire again after a
 value recovers above the threshold and later drops below it.
+Status alerts wait until the new status has persisted for 10 minutes. Returning
+to the last confirmed status cancels the pending alert, so brief flip-flops
+produce no status notifications. A different pending status restarts the timer.
+Pending changes are saved across cron runs; alerts are sent on the first run
+at or after the 10-minute mark. This delay applies only to status notifications:
+battery/runtime alerts and automatic shutdowns still use the current readings.
 Battery-charge alerts start after 10 valid measurements have been collected;
 using their rolling mean prevents a single erroneous `0%` report from causing
 a false alarm. Raw measurements are still stored in the RRD and graphed.