- 1 constructor site (rng_states u32 init) rewritten to
mapped_pinned::upload_u32_via_pinned.
- 2 warm-path sites (source_indices, donor_indices in relabel_batch)
rewritten to mapped_pinned::upload_i32_via_pinned. The warm sites
re-allocate pinned staging per relabel call — acceptable on this
cold path (HER relabel runs once per epoch).
Adds MappedU32Buffer type to mapped_pinned.rs mirroring MappedI32Buffer,
plus upload_u32_via_pinned helper. Manual Debug impl so warning count
stays at 13.
Audit row appended (Fix 10) in docs/dqn-gpu-hot-path-audit.md.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>