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

backend/app/domain/value_objects/scoring_weights.py

@@ -15,16 +15,16 @@ class ScoringWeights:
     tests: float
     detection_rules: float
     d3fend: float
-    freshness: float
-    platform_diversity: float
+    recency: float
+    severity: float
 
     def __post_init__(self) -> None:
         fields = [
             self.tests,
             self.detection_rules,
             self.d3fend,
-            self.freshness,
-            self.platform_diversity,
+            self.recency,
+            self.severity,
         ]
         for f in fields:
             if f < 0:
@@ -43,6 +43,15 @@ class ScoringWeights:
             tests=40.0,
             detection_rules=25.0,
             d3fend=15.0,
-            freshness=10.0,
-            platform_diversity=10.0,
+            recency=10.0,
+            severity=10.0,
         )
+
+    # Backward-compatible aliases for older API payloads
+    @property
+    def freshness(self) -> float:
+        return self.recency
+
+    @property
+    def platform_diversity(self) -> float:
+        return self.severity