fix: chart order markers not displaying due to timestamp format mismatch

- Fix milliseconds to seconds conversion in parseCustomTime (AdvancedChart & ChartWithOrders)
- Add GetTraderOrdersFiltered to filter orders at database level by symbol/status
- Increase order limit from 50 to 200 for more historical orders
- Group multiple orders at same candle time and show count (B3, S5, etc.)
- Buy markers shown below bar (green), sell markers above bar (red)

store/order.go

@@ -237,6 +237,27 @@ func (s *OrderStore) GetTraderOrders(traderID string, limit int) ([]*TraderOrder
 	return orders, nil
 }
 
+// GetTraderOrdersFiltered gets trader's order list with optional symbol and status filters
+func (s *OrderStore) GetTraderOrdersFiltered(traderID string, symbol string, status string, limit int) ([]*TraderOrder, error) {
+	var orders []*TraderOrder
+	query := s.db.Where("trader_id = ?", traderID)
+
+	if symbol != "" {
+		query = query.Where("symbol = ?", symbol)
+	}
+	if status != "" {
+		query = query.Where("status = ?", status)
+	}
+
+	err := query.Order("created_at DESC").
+		Limit(limit).
+		Find(&orders).Error
+	if err != nil {
+		return nil, fmt.Errorf("failed to query orders: %w", err)
+	}
+	return orders, nil
+}
+
 // GetOrderFills gets order's fill records
 func (s *OrderStore) GetOrderFills(orderID int64) ([]*TraderFill, error) {
 	var fills []*TraderFill