schedopt-v3-restarts

Phase B of the v3 campaign. If fixed-concentration training stalls on a heavy tail of seeds, the classical remedy is not a schedule but random restarts, and any tail-truncation claim for a schedule must beat that remedy at matched compute. This node re-tunes the fixed-$\alpha$ baseline for the v3 objective with no incumbency, then stands up two restart baselines over it: the universal Luby cutoff sequence and an oracle fixed cutoff chosen on calibration data, both simulated from a large bank of independent fixed-$\alpha$ runs and validated by real restart chains executed end to end. The comparison of the descent schedule against these policies is the campaign's honest control: if restarts match the schedule, the headline changes.