harden delivery pipeline and production runtime

tests/ml/test_feature_store.py

@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-import pytest
-
 from app.ml.feature_store import FeatureStore, FeatureVector
 
 
@@ -31,12 +29,18 @@ def test_add_batch_appends_all_vectors() -> None:
     ]
     store.add_batch(vectors)
     assert len(store.all()) == 3
-    assert store.latest("sensor.kitchen").values["temperature"] == 20.0
+    latest = store.latest("sensor.kitchen")
+    assert latest is not None
+    assert latest.values["temperature"] == 20.0
 
 
 def test_different_sensors_are_stored_independently() -> None:
     store = FeatureStore()
     store.add(_vector("sensor.living_room", 21.0))
     store.add(_vector("sensor.bedroom", 18.5))
-    assert store.latest("sensor.living_room").values["temperature"] == 21.0
-    assert store.latest("sensor.bedroom").values["temperature"] == 18.5
+    living_room = store.latest("sensor.living_room")
+    bedroom = store.latest("sensor.bedroom")
+    assert living_room is not None
+    assert bedroom is not None
+    assert living_room.values["temperature"] == 21.0
+    assert bedroom.values["temperature"] == 18.5