release v3: add judge_generate.py (scope check, Judge regeneration, manifest verification) (part 2)

release v2: add frozen Judge trainer (slime reward, prompts, pool, launch) and heldout_prompts.jsonl (part 2)

release v1: 65 held-out tasks, 78 bootstrap records, r2e_local adapter, manifest ae94c40b (part 5)