test(icp): add comprehensive tests for full-scene ICP pipeline + update docs

py_workspace/README.md

@@ -162,4 +162,21 @@ uv run refine_ground_plane.py \
 - `--max-rotation-deg`: Safety limit for the correction rotation (default: 5.0).
 - `--max-translation-m`: Safety limit for the correction translation (default: 0.5).
 - `--stride`: Pixel stride for depth sampling (default: 4). Increase for faster processing.
+- `--icp`: Enable ICP refinement after ground plane alignment.
+- `--icp-region`: Region to use for ICP registration (floor, hybrid, full) (default: hybrid).
+- `--icp-global-init`: Enable FPFH+RANSAC global pre-alignment (default: False).
+- `--icp-min-overlap`: Minimum overlap area/volume to accept a pair (default: 0.5).
+- `--icp-band-height`: Height of the floor band in meters (default: 0.3).
+- `--icp-robust-kernel`: Robust kernel for ICP optimization (none, tukey) (default: none).
+- `--icp-robust-k`: Parameter k for robust kernel (default: 0.1).
+
+**Hybrid Mode Example:**
+Refine using both floor and vertical structures (walls/pillars) with global initialization:
+```bash
+uv run refine_ground_plane.py \
+    --input-extrinsics output/extrinsics.json \
+    --input-depth output/depth_data.h5 \
+    --output-extrinsics output/extrinsics_refined.json \
+    --icp --icp-region hybrid --icp-global-init
+```