Use for staffing obligations: salaried employees who are paid regardless
of whether they work, or contracted staff who must be rostered. The solver
ensures each targeted member has at least one assignment per scheduling week.Always a soft constraint (HIGH priority internally). The schedule still
generates when a member genuinely cannot be placed (e.g., full week of
absences). Violations surface as validation warnings with distinct
messaging from minDaysPerWeek. Priority is not configurable;
the rule name communicates the intent.