Justified by live data: sampler phase timing shows sampling at 89% of
the chain node, all 792 quantized layers on the fast path, and the probe
puts dynamic input quantization at ~0.30 ms/layer-call vs ~0.11 ms with
a provided scale (amax dominates) - a top-line per-call cost.
New input_scales widget on the loader:
- "auto-calibrate", first load without a sidecar: forward-pre-hooks
record each quantized layer's running input amax (one generation is
enough; sidecar under refinements/nvfp4_scales/<checkpoint>.json,
per-machine and rebuilt in one run whenever absent).
- every later load: injects input_scale = amax * 1.25 / (448*6) into
the state dict next to each quantized weight - core's loader
registers it natively and skips the per-call amax from then on.
Margin leaves clip headroom (NVFP4 clips above the scale).
Tests: suffix-matched injection across checkpoint prefixes, value math,
core Linear registering input_scale and forwarding, sidecar read.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
