V3 BC Pretrain Checkpoints

BC pretrained strategic model checkpoints (18M params, 1024 hidden, 8 blocks).
Trained on 12,968 transitions from 773 trajectory files (floor 8-16 games).

Checkpoint	BC Epochs	Accuracy	Loss	Eval Avg Floor	Peak
bc_100ep_v3.pt	100	66.7%	0.79	8.0	16
bc_10ep_v3.pt	10	43.4%	1.46	8.1	16

Usage: model.load("checkpoints/bc_10ep_v3.pt")