Window dashboard Money Saved to 30-day average

internal/db/queries.go

@@ -1040,11 +1040,16 @@ func (s *Store) GetDashboardStats(ctx context.Context) (*DashboardStats, error)
 	`).Scan(&d.UnpricedCount); err != nil {
 		return nil, err
 	}
+	// "Money saved" compares each item's current best price against its recent
+	// market average. The average is windowed to the last 30 days so stale
+	// historical prices don't anchor the baseline; items whose only price
+	// history predates the window simply don't contribute an estimate.
 	rows, err := s.DB.QueryContext(ctx, `
 		SELECT i.best_price, AVG(p.price) AS avg_price
 		FROM items i
 		JOIN price_history p ON p.item_id = i.id
 		WHERE i.active = 1 AND i.best_price IS NOT NULL
+		  AND p.polled_at >= datetime('now', '-30 day')
 		GROUP BY i.id
 	`)
 	if err != nil {