refactor(vo): address code review for CuVSLAMMonoDepthVisualOdometry

- test_depth_hint_scales_translation: replace assert True with mock-based verification of scale factor
- _init_tracker / _compute_via_cuvslam: logger.exception for stack traces
- _init_tracker: loud warning when Jetson path disabled
- drop personal attribution (git blame suffices)
- translate Ukrainian test docstrings to English

tests/test_vo.py

@@ -230,14 +230,14 @@ def test_create_vo_backend_orb_fallback():
 # ---------------------------------------------------------------------------
 
 def test_mono_depth_implements_interface():
-    """CuVSLAMMonoDepthVisualOdometry реалізує ISequentialVisualOdometry."""
+    """CuVSLAMMonoDepthVisualOdometry implements ISequentialVisualOdometry."""
     from gps_denied.core.vo import CuVSLAMMonoDepthVisualOdometry
     vo = CuVSLAMMonoDepthVisualOdometry(depth_hint_m=600.0)
     assert isinstance(vo, ISequentialVisualOdometry)
 
 
 def test_mono_depth_scale_not_ambiguous():
-    """Mono-Depth backend завжди повертає scale_ambiguous=False."""
+    """Mono-Depth backend always returns scale_ambiguous=False."""
     from gps_denied.core.vo import CuVSLAMMonoDepthVisualOdometry
     vo = CuVSLAMMonoDepthVisualOdometry(depth_hint_m=600.0)
     prev = np.zeros((480, 640), dtype=np.uint8)
@@ -247,38 +247,57 @@ def test_mono_depth_scale_not_ambiguous():
         resolution_width=640, resolution_height=480,
     )
     pose = vo.compute_relative_pose(prev, curr, cam)
-    # може бути None якщо зображення порожні — але якщо є, scale_ambiguous=False
+    # may be None when images are blank — but if present, scale_ambiguous=False
     if pose is not None:
         assert pose.scale_ambiguous is False
 
 
 def test_mono_depth_depth_hint_scales_translation():
-    """depth_hint_m впливає на масштаб translation у dev/CI fallback."""
-    from gps_denied.core.vo import CuVSLAMMonoDepthVisualOdometry
-    import cv2
-
-    # Синтетичні зображення з реальними features щоб ORB знайшов matches
-    rng = np.random.default_rng(42)
-    img = (rng.integers(0, 255, (480, 640), dtype=np.uint8))
+    """depth_hint_m масштабує translation у dev/CI ORB fallback by depth_hint_m / 600.0."""
+    from unittest.mock import patch
+    from gps_denied.core.vo import CuVSLAMMonoDepthVisualOdometry, ORBVisualOdometry
+    from gps_denied.schemas.vo import RelativePose
 
     cam = CameraParameters(
         focal_length=16.0, sensor_width=23.2, sensor_height=17.4,
         resolution_width=640, resolution_height=480,
     )
+    img = np.zeros((480, 640), dtype=np.uint8)
 
-    vo_low = CuVSLAMMonoDepthVisualOdometry(depth_hint_m=300.0)
-    vo_high = CuVSLAMMonoDepthVisualOdometry(depth_hint_m=600.0)
+    # Mock ORB to always return a unit translation — lets us verify the scale factor cleanly
+    unit_pose = RelativePose(
+        translation=np.array([1.0, 0.0, 0.0]),
+        rotation=np.eye(3),
+        confidence=1.0,
+        inlier_count=100,
+        total_matches=100,
+        tracking_good=True,
+        scale_ambiguous=True,
+    )
 
-    pose_low = vo_low.compute_relative_pose(img, img, cam)
-    pose_high = vo_high.compute_relative_pose(img, img, cam)
+    with patch.object(ORBVisualOdometry, "compute_relative_pose", return_value=unit_pose):
+        vo_300 = CuVSLAMMonoDepthVisualOdometry(depth_hint_m=300.0)
+        vo_600 = CuVSLAMMonoDepthVisualOdometry(depth_hint_m=600.0)
+        vo_1200 = CuVSLAMMonoDepthVisualOdometry(depth_hint_m=1200.0)
 
-    # Обидва можуть повернути None для ідентичних зображень (нульовий motion)
-    # Тест верифікує що клас існує і приймає depth_hint_m без помилок
-    assert True  # якщо дійшли сюди — конструктор і interface працюють
+        pose_300 = vo_300.compute_relative_pose(img, img, cam)
+        pose_600 = vo_600.compute_relative_pose(img, img, cam)
+        pose_1200 = vo_1200.compute_relative_pose(img, img, cam)
+
+    # At 600m reference altitude, scale = 1.0 → unchanged
+    assert np.allclose(pose_600.translation, [1.0, 0.0, 0.0])
+    # At 300m, scale = 0.5 → halved
+    assert np.allclose(pose_300.translation, [0.5, 0.0, 0.0])
+    # At 1200m, scale = 2.0 → doubled
+    assert np.allclose(pose_1200.translation, [2.0, 0.0, 0.0])
+    # All must report metric scale
+    assert pose_300.scale_ambiguous is False
+    assert pose_600.scale_ambiguous is False
+    assert pose_1200.scale_ambiguous is False
 
 
 def test_mono_depth_create_vo_backend_selects_it():
-    """create_vo_backend з prefer_mono_depth=True повертає CuVSLAMMonoDepthVisualOdometry."""
+    """create_vo_backend with prefer_mono_depth=True returns CuVSLAMMonoDepthVisualOdometry."""
     from gps_denied.core.vo import CuVSLAMMonoDepthVisualOdometry, create_vo_backend
     vo = create_vo_backend(prefer_mono_depth=True, depth_hint_m=600.0)
     assert isinstance(vo, CuVSLAMMonoDepthVisualOdometry)