Replace individual new-note emails with an administrator digest

For the established (legacy) Volunteer Management portal. These steps differ from the newer Volunteer Management interface. Staff access is determined by their assigned administrator role(s). Administrator roles have fixed capabilities; the configurable volunteer roles described here are separate from staff administrator roles.

In established VMS Administrators, locate the staff member and set Digest Email Notifications to Yes, then confirm. New volunteer-note notifications to eligible handlers are queued into the daily digest instead of being sent individually when this setting is enabled. Setting it to No restores individual notifications; it is not an off switch. This also affects other supported digest notifications and does not confirm a note-only mute. Updated-note notifications have a separate send path, so inspect the actual message type if those still arrive individually. The setting is not shown on every system-school administrative view.