Properties
Shift assignments (empty when infeasible or no solution).
Cost breakdown for optimized solves when cost rules are used and a solution is found.
Outcome of the solve attempt.
Schedule Definition
SolveResult
Result of Schedule.solve.
Feasibility-only solves return hard-feasible assignments when one is found,
but they do not optimize objectives or compute objective-derived metadata.
Cost is therefore only produced for optimized solves.