CUDA map normal cache: cold compiler cache

Scope	Previous (s)	Lazy fused normals (s)	Ratio
Complete fresh process	18.812822	16.997728	1.107x
Complete map evaluation API	13.667212	11.648084	1.173x

All 6 processes are retained, including first initialization and compilation. The cold cohort has 3 alternating pairs. Cold mode starts each worker with a separate empty cache. Retained mode starts each method's cache empty and retains it across its subsequent fresh processes. No warmup, timing exclusions or discarded observations enter these medians.

Every original byte is preserved, including operator input paths in provenance. The prior revision is 3340116c2b0c1a7c0cd1aa3b29468a44d4fc330f; the current revision is 8d7a6477343d2a727ae02c86704fe8c76f894c5c. Both source trees, actual-import hashes, exact launchers/schema, complete observations/results, timings and cache-file hashes are bound by publication-index.json. Raw scans and compiler binaries are external. The measurements use an unreserved host and are descriptive, with no portable speed guarantee. This is the existing copied-sensor KITTI execution control, not independent two-LiDAR calibration accuracy or bag decoding/odometry timing.

See scope and reproduction.

python -m tools.audit_cuda_map_preparation docs/assets/cuda_map_normal_cache/cold