Adds runners for HillClimber, SimulatedAnnealing, GeneticAlgorithm, ParticleSwarm, CmaEs, and Umda to `examples/compare.rs`. Rastrigin section now compares 8 single-objective optimizers against each other on a fixed evaluation budget. The MO sections (ZDT1, DTLZ2) are unchanged for now — MOPSO and IBEA get added in a follow-up commit so each algorithm's debut shows up clearly in the harness.