Update volunteer dashboard campaign

For the established (legacy) Volunteer Management portal. These steps differ from the newer Volunteer Management interface. Administrator controls require the appropriate school or volunteer-management permissions.

Use VMS Roles → Fundraising Campaign Settings to change the affected role's fundraising-dashboard campaign association, save, then preview as that role. This dashboard association is separate from other campaign/email/call-to-action settings. If the intended current campaign is not selectable, review available campaigns and product access.