feat: wire safetensors BF16 pipeline for Qwen3.5 → Claude reasoning scaffold

5 models (27B base/v1/v2 + 9B base/dist), 4 diffs, per-shard diffing
with aggregated stats, scaffold detection, NARS revision, and results
output. Fixes classify_projection for GGUF-style "embd" tensor names.

https://claude.ai/code/session_01M3at4EuHVvQ8S95mSnKgtK

Author: claude