fix(observatory): preserve camera across follow transitions

tests/test_recorded_camera_bounds.py

@@ -5,7 +5,10 @@ import pytest
 import rerun as rr
 
 import k1link.viewer.recorded_camera_bounds as camera_bounds
-from k1link.viewer.recorded_camera_bounds import recorded_orbital_radius_limit
+from k1link.viewer.recorded_camera_bounds import (
+    recorded_orbital_radius_limit,
+    recorded_tracking_position,
+)
 
 
 def _recording(path: Path) -> None:
@@ -14,8 +17,10 @@ def _recording(path: Path) -> None:
     try:
         recording.set_time("session_time", duration=np.timedelta64(10, "s"))
         recording.log("/world/points", rr.Points3D([[0, 0, 0], [3, 4, 0]]))
+        recording.log("/world/sensor_pose", rr.Transform3D(translation=[1, 2, 3]))
         recording.set_time("session_time", duration=np.timedelta64(20, "s"))
         recording.log("/world/points", rr.Points3D([[10, 0, 0], [10, 0, 12]]))
+        recording.log("/world/sensor_pose", rr.Transform3D(translation=[10, 20, 30]))
         recording.flush(timeout_sec=5)
     finally:
         recording.disconnect()
@@ -84,3 +89,18 @@ def test_recorded_camera_queries_reuse_the_generation_bounds_index(tmp_path: Pat
     assert second == pytest.approx(60, rel=1e-6)
     assert cache.misses == 1
     assert cache.hits == 1
+
+
+def test_recorded_tracking_position_uses_latest_pose_at_cursor(tmp_path: Path) -> None:
+    path = tmp_path / "recording.rrd"
+    _recording(path)
+
+    assert recorded_tracking_position(path, current_time_ns=9_000_000_000) is None
+    assert recorded_tracking_position(
+        path,
+        current_time_ns=15_000_000_000,
+    ) == pytest.approx((1, 2, 3))
+    assert recorded_tracking_position(
+        path,
+        current_time_ns=20_000_000_000,
+    ) == pytest.approx((10, 20, 30))

tests/test_rrd_export.py

@@ -627,8 +627,9 @@ def test_recorded_blueprint_updates_reuse_source_store_and_opt_in_to_activation(
     assert eye_control_updates == [True, False, True, False, True]
     # Reactivating a blueprint clone is required for visible layer changes, but
     # those changes must not write position/look-target/eye-up and reset the
-    # operator's camera. Only the follow transition writes a spatial preset.
-    assert explicit_presets == [False, False, True, False, False]
+    # operator's camera. Follow only changes tracking; it must not write the
+    # startup eye. 3D/plan remains the explicit spatial preset transition.
+    assert explicit_presets == [False, False, False, False, False]
     assert [activation[1:] for activation in activations] == [
         (True, False),
         (reactivate_updates, False),

tests/test_session_api.py

@@ -1796,6 +1796,7 @@ def test_recorded_blueprint_restores_camera_bounds_after_base_launch_lease_expir
     store.reconcile_archive(xgrids_k1_archive_source(sessions))
     recording_path = tmp_path / "published.rrd"
     calls: list[tuple[Path, dict[str, object]]] = []
+    blueprint_calls: list[dict[str, object]] = []
 
     class PublishedMaterializer:
         def restore_published(self, command: ReplayCommand) -> object:
@@ -1806,11 +1807,19 @@ def test_recorded_blueprint_restores_camera_bounds_after_base_launch_lease_expir
         calls.append((path, kwargs))
         return 123.5
 
+    def blueprint_payload(*_args: object, **kwargs: object) -> bytes:
+        blueprint_calls.append(kwargs)
+        return b"RRF2"
+
     monkeypatch.setattr(
         "k1link.web.session_api.recorded_blueprint_rrd",
-        lambda *_args, **_kwargs: b"RRF2",
+        blueprint_payload,
     )
     monkeypatch.setattr("k1link.web.session_api.recorded_orbital_radius_limit", camera_bounds)
+    monkeypatch.setattr(
+        "k1link.web.session_api.recorded_tracking_position",
+        lambda *_args, **_kwargs: (100.0, 200.0, 300.0),
+    )
     route = endpoint(
         build_session_router(store, recording_materializer=PublishedMaterializer()),  # type: ignore[arg-type]
         "/api/v1/observation-sessions/{session_id}/blueprint.rrd",
@@ -1828,6 +1837,11 @@ def test_recorded_blueprint_restores_camera_bounds_after_base_launch_lease_expir
                 show_points=True,
                 show_trajectory=False,
                 show_grid=True,
+                follow_trajectory=False,
+                eye_position=(3.0, 4.0, 5.0),
+                eye_look_target=(1.0, 2.0, 0.0),
+                eye_up=(0.0, 0.0, 1.0),
+                eye_relative_to_tracking=True,
                 current_time_ns=39_215_000_000,
             ),
         )
@@ -1845,6 +1859,9 @@ def test_recorded_blueprint_restores_camera_bounds_after_base_launch_lease_expir
             },
         )
     ]
+    assert blueprint_calls[0]["eye_position"] == pytest.approx((102.0, 202.0, 305.0))
+    assert blueprint_calls[0]["eye_look_target"] == pytest.approx((100.0, 200.0, 300.0))
+    assert blueprint_calls[0]["eye_up"] == (0.0, 0.0, 1.0)
 
 
 def test_recorded_perception_endpoint_returns_one_complete_optional_overlay(