## Notes
- Used `scipy.spatial.transform.Rotation` with `xyz` Euler convention for gravity regularization to ensure consistent blending of pitch/roll.
- `extract_near_floor_band` uses dot product with floor normal to handle arbitrary floor orientations (not just Y-up).
- `refine_with_icp` uses a BFS-based connectivity check to ensure only cameras reachable from the reference camera are optimized.