Shared Assignments disablement and Selectable rules

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.

Shared Assignments is a feature enablement controlled by GiveCampus, rather than an ordinary role-setting checkbox. Disabling it does not itself unpair all existing assignments; review existing shared assignments explicitly. With sharing disabled, assignment CSV loading does not add a second simultaneous assignment to an already assigned constituent unless the overwrite workflow replaces the prior assignment. Manual administrator assignment likewise replaces the previous volunteer rather than bypassing the non-shared rule. A constituent marked unselectable remains unavailable for new volunteer self-selection even when Shared Assignments is enabled; that flag controls selection, not an automatic removal of existing assignments.