1. History entries saved at the same time by the same user now display
as a single grouped entry (resolution date + remediation plan together)
2. Removed '(optional)' from the change reason placeholder — engineers
should treat it as expected, even though the backend allows empty
3. Save button now saves both resolution date AND remediation plan in one
call (removed the onBlur auto-save on the date field) so they share
a timestamp and group correctly in history
4d255209fd
