fix: ensure all timestamps use UTC timezone

- Add NowFunc to GORM config for UTC auto-generated timestamps
- Add .UTC() to all time.UnixMilli() calls in trader files
- Add .UTC() to all time.Now() calls in store and api files
- Fix TypeScript unused imports in frontend

trader/auto_trader.go

@@ -637,7 +637,7 @@ func (at *AutoTrader) runCycle() error {
 			TakeProfit: d.TakeProfit,
 			Confidence: d.Confidence,
 			Reasoning:  d.Reasoning,
-			Timestamp:  time.Now(),
+			Timestamp:  time.Now().UTC(),
 			Success:    false,
 		}
 
@@ -1976,7 +1976,7 @@ func (at *AutoTrader) recordPositionChange(orderID, symbol, side, action string,
 			Quantity:     quantity,
 			EntryPrice:   price,
 			EntryOrderID: orderID,
-			EntryTime:    time.Now(),
+			EntryTime:    time.Now().UTC(),
 			Leverage:     leverage,
 			Status:       "OPEN",
 		}
@@ -1996,7 +1996,7 @@ func (at *AutoTrader) recordPositionChange(orderID, symbol, side, action string,
 			at.id, at.exchangeID, at.exchange,
 			symbol, side, action,
 			quantity, price, fee, 0, // realizedPnL will be calculated
-			time.Now(), orderID,
+			time.Now().UTC(), orderID,
 		); err != nil {
 			logger.Infof("  ⚠️ Failed to process close position: %v", err)
 		} else {
@@ -2049,8 +2049,8 @@ func (at *AutoTrader) createOrderRecord(orderID, symbol, action, positionSide st
 		ReduceOnly:      reduceOnly,
 		ClosePosition:   reduceOnly,
 		OrderAction:     orderAction,
-		CreatedAt:       time.Now(),
-		UpdatedAt:       time.Now(),
+		CreatedAt:       time.Now().UTC(),
+		UpdatedAt:       time.Now().UTC(),
 	}
 }
 
@@ -2091,7 +2091,7 @@ func (at *AutoTrader) recordOrderFill(orderRecordID int64, exchangeOrderID, symb
 		CommissionAsset:  "USDT",
 		RealizedPnL:      0, // Will be calculated for close orders
 		IsMaker:          false, // Market orders are usually taker
-		CreatedAt:        time.Now(),
+		CreatedAt:        time.Now().UTC(),
 	}
 
 	// Calculate realized PnL for close orders