feat(scoring): composite recency decay and severity weights persisted in DB [FASE-5.1]

backend/tests/test_value_objects.py

@@ -84,13 +84,13 @@ class TestScoringWeights:
         assert w.tests == 40.0
         assert w.detection_rules == 25.0
         assert w.d3fend == 15.0
-        assert w.freshness == 10.0
-        assert w.platform_diversity == 10.0
+        assert w.recency == 10.0
+        assert w.severity == 10.0
 
     def test_valid_custom(self):
         w = ScoringWeights(
             tests=50, detection_rules=20, d3fend=10,
-            freshness=10, platform_diversity=10,
+            recency=10, severity=10,
         )
         assert w.tests == 50
 
@@ -98,14 +98,14 @@ class TestScoringWeights:
         with pytest.raises(ValueError, match="sum to 100"):
             ScoringWeights(
                 tests=50, detection_rules=20, d3fend=10,
-                freshness=10, platform_diversity=5,
+                recency=10, severity=5,
             )
 
     def test_invalid_negative_weight(self):
         with pytest.raises(ValueError, match="non-negative"):
             ScoringWeights(
                 tests=-10, detection_rules=40, d3fend=30,
-                freshness=20, platform_diversity=20,
+                recency=20, severity=20,
             )
 
     def test_immutable(self):