feat: adjust confidence calculation in score fusion to improve agreement handling

app/services/score_fusion.py

@@ -286,23 +286,18 @@ def _fuse(
 
     mode: str = "production"
 
-    # Clamp to valid range
-    confidence = max(0.51, min(0.97, confidence))
-    confidence = round(confidence, 4)
-
-    # Agreement bonus
+    # Agreement bonus/dampen
     if len(scores) > 1:
         all_ai = all(s > 0.5 for s, _, _ in scores)
         all_human = all(s <= 0.5 for s, _, _ in scores)
         if all_ai:
-            # More layers agreeing → bigger boost
             boost = 1.0 + 0.02 * len(scores)
             confidence = min(0.97, confidence * boost)
         elif all_human:
             dampen = 1.0 - 0.02 * len(scores)
-            confidence = max(0.51, confidence * dampen)
+            confidence = max(0.03, confidence * dampen)
 
-    confidence = round(max(0.51, min(0.97, confidence)), 4)
+    confidence = round(max(0.03, min(0.97, confidence)), 4)
 
     sources_str = ", ".join(f"{src}={s:.3f}" for s, _, src in scores)
     logger.info(