[AZ-221] [AZ-222] Add shared runtime helpers

Provide deterministic geometry/time-sync helpers and structured config, error, health, and telemetry primitives for downstream runtime components.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/unit/shared/test_geometry_time_sync.py

@@ -0,0 +1,41 @@
+from shared.geo_geometry import Wgs84Coordinate, distance_m, local_to_wgs84, wgs84_to_local
+from shared.time_sync import check_monotonic_timestamps, select_time_window
+
+
+def test_wgs84_local_round_trip_is_deterministic() -> None:
+    # Arrange
+    origin = Wgs84Coordinate(latitude_deg=49.9808, longitude_deg=36.2527, altitude_m=120.0)
+    point = Wgs84Coordinate(latitude_deg=49.9811, longitude_deg=36.2531, altitude_m=118.0)
+
+    # Act
+    local = wgs84_to_local(origin, point)
+    round_trip = local_to_wgs84(origin, local)
+
+    # Assert
+    assert round(round_trip.latitude_deg, 7) == round(point.latitude_deg, 7)
+    assert round(round_trip.longitude_deg, 7) == round(point.longitude_deg, 7)
+    assert round(round_trip.altitude_m, 7) == round(point.altitude_m, 7)
+    assert distance_m(origin, point) > 0.0
+
+
+def test_non_monotonic_timestamps_return_explicit_violation() -> None:
+    # Act
+    violations = check_monotonic_timestamps([100, 200, 150])
+
+    # Assert
+    assert len(violations) == 1
+    assert violations[0].category == "timestamp_mismatch"
+
+
+def test_time_window_reports_gap_instead_of_dropping_silently() -> None:
+    # Act
+    result = select_time_window(
+        frame_timestamp_ns=1_000,
+        sample_timestamps_ns=[100, 200, 300],
+        tolerance_ns=50,
+    )
+
+    # Assert
+    assert result.ok is False
+    assert result.sample_timestamps_ns == ()
+    assert result.violations[0].category == "gap_exceeded"