Add `compute_dtype` field to ModelConfig ("bf16", "fp8", "fp4") which
controls two things:
- GPU FLOPS tier: auto-selects from preset FP4/FP8/BF16 TFLOPS
- Weight bytes: uses 0.5/1.0/2.0 bytes per param for memory-bound check
Hardware presets now include per-GPU FP8 and FP4 dense FLOPS for all
GPUs that support them (H100/H800/H20: FP8, B200/B300: FP8+FP4).
Config resolution auto-selects the right FLOPS when compute_dtype is
set and the user hasn't explicitly overridden gpu_flops.
GLM-5-NVFP4 on 8xB300 now correctly uses 13.5 PFLOPS/GPU FP4 (6x
faster prefill) and 0.5 bytes/param weights (halved memory footprint).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>