Update model references: Llama 3.3 70B → Llama 3.1 8B Instant, runtime 19.8min → ~10min

Update greedy baseline numbers from latest test_local run; recalculate lifts

Reduce rollouts easy=2 medium=3 hard=3 — target ~15min runtime with buffer for judge overhead

Cut easy rollouts 3→2 to stay under 20min; update GRPO scores; fill config/tasks.yaml

Initial submission: Cascade Containment