fix(icp): relax success gate to >0 and add per-pair diagnostic logging

py_workspace/tests/test_icp_registration.py

@@ -292,8 +292,8 @@ def test_refine_with_icp_no_overlap():
             camera_data, extrinsics, floor_planes, config
         )
 
-        assert not metrics.success
-        assert "No converged ICP pairs" in metrics.message
+        assert metrics.num_cameras_optimized == 1
+        assert metrics.success
 
     finally:
         aruco.ground_plane.unproject_depth_to_points = orig_unproject
@@ -309,4 +309,5 @@ def test_refine_with_icp_single_camera():
         camera_data, extrinsics, floor_planes, config
     )
 
-    assert not metrics.success
+    assert metrics.num_cameras_optimized == 1
+    assert metrics.success