mttr generated column is now integer minutes (source raw.mttr is decimal hours),
analytics-friendly. Drop is_alarm/is_auto_created/is_auto_closed generated columns
— all constant `false` in tickets.inc since alarms are filtered at ingest (still
present in raw for audit; loader still filters on raw->>'is_alarm'). is_actionable
kept.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
