perf(exp4): trainer memory + visibility — freeze layers, batch 1, step logging, mid-epoch ckpt

fix(exp4): trainer crashed at loss — build mask/class labels explicitly

feat(exp4): verdicts_to_exclude.py — review verdicts -> trainer exclude-file

fix(exp4): review-page export works in the artifact sandbox (mobile)

revert(exp4): labeler back to 648016a baseline — drop patio class + shadow repairs

feat(exp4): patio/deck class + shared taxonomy + frozen review legend

fix(exp4): per-round verdict namespace on review pages

feat(exp4): lighting-invariant label repairs from owner round-1 review

fix(exp4): review-page export works on mobile — verdicts shown in a copyable box

feat(exp4): tune SAM-3 fusion on smoke evidence — dormant turf is LAWN

feat(exp4): --purge-lidar flag — cap exporter disk to ~1 cluster of tiles

feat(exp4): Phase 2/3 engine — crop exporter, SAM-3 auto-labeler, review page, trainer