navigation: live Rerun visualization of the map (+ dynamic carving)

MapVisualizer (lazy rerun-sdk, lerobot[viz]) streams the map as it builds:
voxel cloud (RGB or recency colormap), robot pose, top-down occupancy,
planned path, and the located target. The dynamic part is visible — each
keyframe re-logs the full snapshot so carved voxels vanish, and this
frame's removed voxels flash red under world/carved.

Wired into LiveMapper.tick (per-keyframe map/removed/robot) and
DogController (map/occupancy/robot/target/path after each action), behind
a --viz flag (+ --color-mode rgb|recency) on dog-nav; works in --dry-run,
--map-only, and --live. Headless tests (spawn=False) cover the log paths
and a full dry-run navigate-with-viz. 140 tests in tests/navigation/.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/navigation/test_viz.py

@@ -0,0 +1,88 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Headless tests for the Rerun map visualizer.
+
+``spawn=False`` buffers to an in-memory recording, so these run without a
+display and skip cleanly when rerun-sdk isn't installed.
+"""
+
+from __future__ import annotations
+
+import numpy as np
+import pytest
+
+pytest.importorskip("rerun", reason="rerun-sdk not installed (pip install 'lerobot[viz]')")
+
+from lerobot.navigation.dog_cli import _build_dry_run  # noqa: E402
+from lerobot.navigation.viz import MapVisualizer, _recency_colors  # noqa: E402
+from lerobot.navigation.voxel_map import VoxelMap  # noqa: E402
+
+
+def test_recency_colors_recent_vs_old():
+    last = np.array([10.0, 0.0])  # one recent, one old
+    colors = _recency_colors(last, now=10.0, horizon_s=10.0)
+    assert colors.shape == (2, 3)
+    assert colors.dtype == np.uint8
+    # Recent voxel (age 0) is more green/cyan; old (age 1) is more red.
+    assert colors[0, 1] > colors[1, 1]  # green channel higher for recent
+    assert colors[1, 0] > colors[0, 0]  # red channel higher for old
+
+
+def _viz() -> MapVisualizer:
+    return MapVisualizer(app_id="test-dog-nav", spawn=False)
+
+
+def test_log_map_and_dynamics_do_not_raise():
+    viz = _viz()
+    vm = VoxelMap(voxel_size=0.1)
+    pts = np.array([[[0.0, 0.0, 1.0]], [[0.1, 0.0, 1.0]]], dtype=np.float64)
+    rgb = np.full((2, 1, 3), 200, dtype=np.uint8)
+    conf = np.ones((2, 1), dtype=np.float32)
+    vm.add(pts, rgb, conf, frame=0, t=0.0)
+
+    viz.set_time(0.0)
+    viz.log_map(vm.snapshot(), now=0.0)
+    viz.log_removed(np.array([[0.5, 0.0, 1.0]], dtype=np.float32))  # a carved voxel
+    viz.log_robot(np.eye(4))
+    viz.log_path([(0.0, 0.0, 0.0), (0.5, 0.0, 0.5)])
+    viz.log_target((0.1, 0.0, 1.0))
+
+
+def test_log_empty_map_clears_cleanly():
+    viz = _viz()
+    viz.set_time(1.0)
+    viz.log_map(VoxelMap().snapshot())  # empty
+    viz.log_removed(np.zeros((0, 3), dtype=np.float32))
+    viz.log_target(None)
+
+
+def test_recency_color_mode():
+    viz = MapVisualizer(app_id="test-recency", spawn=False, color_mode="recency")
+    vm = VoxelMap(voxel_size=0.1)
+    pts = np.array([[[0.0, 0.0, 1.0]]], dtype=np.float64)
+    vm.add(pts, np.full((1, 1, 3), 100, np.uint8), np.ones((1, 1), np.float32), frame=0, t=5.0)
+    viz.set_time(5.0)
+    viz.log_map(vm.snapshot(), now=5.0)
+
+
+def test_dry_run_controller_with_viz_navigates():
+    """End-to-end: the dry-run stack with a headless visualizer still reaches
+    the couch, and every viz call along the way is exercised."""
+    viz = _viz()
+    controller = _build_dry_run(viz=viz)
+    result = controller.handle_prompt("couch")
+    assert result.fully_successful