feat: complete comprehensive zero-state metrics across all dashboard pages for new accounts

backend/predictor.py

@@ -17,7 +17,19 @@ def calculate_readiness_score(user_id: UUID, session: Session) -> dict:
     ).all()
     
     if not attempts:
-        return {"score": 0, "status": "Not enough data"}
+        return {
+            "score": 0,
+            "status": "Not enough data",
+            "prediction": "Start practice to calculate",
+            "target_type": "Unranked",
+            "breakdown": {
+                "accuracy": 0,
+                "speed": 0,
+                "consistency": 0,
+                "recovery": 0,
+                "coverage": 0,
+            }
+        }
 
     # 1. Accuracy (40% Weight)
     avg_accuracy = sum(a.accuracy for a in attempts) / len(attempts)