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)

api/server.go

@@ -2294,28 +2294,14 @@ func (s *Server) handleOrders(c *gin.Context) {
 		return
 	}
 
-	// Get all orders for this trader
-	allOrders, err := store.Order().GetTraderOrders(trader.GetID(), limit)
+	// Get orders with filters applied at database level
+	orders, err := store.Order().GetTraderOrdersFiltered(trader.GetID(), symbol, statusFilter, limit)
 	if err != nil {
 		SafeInternalError(c, "Get orders", err)
 		return
 	}
 
-	// Filter by symbol and status if specified
-	result := make([]interface{}, 0)
-	for _, order := range allOrders {
-		// Filter by symbol
-		if symbol != "" && order.Symbol != symbol {
-			continue
-		}
-		// Filter by status
-		if statusFilter != "" && order.Status != statusFilter {
-			continue
-		}
-		result = append(result, order)
-	}
-
-	c.JSON(http.StatusOK, result)
+	c.JSON(http.StatusOK, orders)
 }
 
 // handleOrderFills Order fill details (all fills for a specific order)