This reports the cause of the most recent HA switchover event using the platform-specific CarSwitchOverReason enumeration, giving an admin the 'why' behind the last time active and standby roles swapped on this appliance pair. This is the first thing an admin would check after noticing a switchover occurred, to distinguish an intentional manual failover (for maintenance) from an unplanned one caused by a detected fault. For example, a reason value corresponding to a failed connectivity check (tied to carRedundancyCheckInterval) would tell the admin the standby promoted itself because it lost contact with the active node, rather than because someone manually triggered the switch.