fix: restore batch_size to GPU profiles — profile defaults, not auto-scaling
Auto-scaling returned 8192 on 4GB RTX 3050 (should be 64), causing
17s/epoch instead of 0.28s. The VRAM math didn't account for IQN (1.1GB),
attention, IQL, replay buffer (70% VRAM).
Profile-tested values:
- RTX 3050: 64 (4GB, minimal)
- A100: 2048 (40-80GB)
- H100: 8192 (80GB, production)
- Default: 256 (conservative)
Auto-scaling remains as fallback for batch_size=0 (unknown GPU).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
f5b21406a8