fix: 手动平仓持久化PnL到DB

ClosePosition/CloseAllPositions 之前只调 closeBothLegs 关交易所仓位
后直接 delete(t.positions)，没有写DB/记PnL/入 closedTrades，
重启后交易数据丢失。

- 新增 finalizeClosedPosition() 共享方法：
  统一处理 PnL计算、exchangeFunds更新、DB持久化(exit orders +
  UpdateTradeStatus)、closedTrades追加、SSE推事件
- ClosePosition/CloseAllPositions 改用该方法
- 手动平仓用入场均价的出场价格，PnL=0，
  原因标记为'手动平仓'/'全部平仓'
- 同时增加 closeBothLegs 失败的处理（之前直接忽略）

trader.go

@@ -348,13 +348,23 @@ func (t *Trader) ClosePosition(coin string) error {
 	if pos.Status != "open" && pos.Status != "close_failed" {
 		return fmt.Errorf("position %s is in status %s, cannot close", coin, pos.Status)
 	}
-	t.closeBothLegs(pos)
+
-	pos.Status = "closed"
+	elapsed := time.Since(pos.StartedAt)
+	closeErr := t.closeBothLegs(pos)
+	if closeErr != "" {
+		pos.Status = "close_failed"
 		pos.ExitedAt = time.Now()
-	t.mu.Lock()
+		pos.ErrorLog = closeErr
-	delete(t.positions, coin)
+		log.Printf("[Trader] ❌ Manual close %s failed: %s", coin, closeErr)
-	t.mu.Unlock()
+		return fmt.Errorf("close failed: %s", closeErr)
-	log.Printf("[Trader] Manually closed %s %s", coin, pos.Direction)
+	}
+
+	// Use entry prices as exit price estimate (manual close — no live price snapshot)
+	longAvg := weightedAvgPrice(pos.LongEntryPrices, t.cfg.TradeAmountUSD)
+	shortAvg := weightedAvgPrice(pos.ShortEntryPrices, t.cfg.TradeAmountUSD)
+
+	t.finalizeClosedPosition(pos, longAvg, shortAvg, 0, 0, 0, 0, 0, longAvg, shortAvg, "手动", "手动平仓", elapsed)
+	log.Printf("[Trader] Manually closed %s %s — persisted to DB", coin, pos.Direction)
 	return nil
 }
 
@@ -369,13 +379,19 @@ func (t *Trader) CloseAllPositions() int {
 	count := 0
 	for _, pos := range positions {
 		if pos.Status == "open" || pos.Status == "close_failed" {
-			t.closeBothLegs(pos)
+			elapsed := time.Since(pos.StartedAt)
-			pos.Status = "closed"
+			closeErr := t.closeBothLegs(pos)
+			if closeErr != "" {
+				pos.Status = "close_failed"
 				pos.ExitedAt = time.Now()
-			t.mu.Lock()
+				pos.ErrorLog = closeErr
-			delete(t.positions, pos.Coin)
+				log.Printf("[Trader] ❌ Force-close %s failed: %s", pos.Coin, closeErr)
-			t.mu.Unlock()
+				continue
-			log.Printf("[Trader] Force-closed %s %s", pos.Coin, pos.Direction)
+			}
+			longAvg := weightedAvgPrice(pos.LongEntryPrices, t.cfg.TradeAmountUSD)
+			shortAvg := weightedAvgPrice(pos.ShortEntryPrices, t.cfg.TradeAmountUSD)
+			t.finalizeClosedPosition(pos, longAvg, shortAvg, 0, 0, 0, 0, 0, longAvg, shortAvg, "手动", "全部平仓", elapsed)
+			log.Printf("[Trader] Force-closed %s %s — persisted to DB", pos.Coin, pos.Direction)
 			count++
 		}
 	}
@@ -1163,6 +1179,165 @@ func (t *Trader) placeOrder(leg *PositionLeg, side string, store *PriceStore) (s
 	}
 }
 
+// finalizeClosedPosition persists a closed position: computes PnL (if not given),
+// records to closedTrades, updates exchangeFunds, persists exit orders + trade to DB.
+// longPct/shortPct/totalFeesPct are % values; pass the price snapshot used at close trigger.
+// longPrice/shortPrice are the exit prices for each leg. Use entry prices if unknown.
+func (t *Trader) finalizeClosedPosition(pos *ArbPosition, longPrice, shortPrice, diffPct, netPnlPct, longPnlPct, shortPnlPct, totalFeesPct, longCurrent, shortCurrent float64, convergence, exitReason string, elapsed time.Duration) {
+	pos.ExitedAt = time.Now()
+	pos.Status = "closed"
+	pos.RealizedPnl = netPnlPct
+
+	// Per-leg PnL and fees in USD
+	numBatches := 1 + pos.ScaleLevels
+	legCapital := t.cfg.TradeAmountUSD
+	longPnlUSD := longPnlPct / 100 * float64(numBatches) * legCapital
+	shortPnlUSD := shortPnlPct / 100 * float64(numBatches) * legCapital
+
+	totalLongShares := 0.0
+	for _, p := range pos.LongEntryPrices {
+		totalLongShares += legCapital / p
+	}
+	totalShortShares := 0.0
+	for _, p := range pos.ShortEntryPrices {
+		totalShortShares += legCapital / p
+	}
+
+	longEntryFeeSum := float64(numBatches) * legCapital * takerFees[pos.LongLeg.Exchange] / 100
+	shortEntryFeeSum := float64(numBatches) * legCapital * takerFees[pos.ShortLeg.Exchange] / 100
+	longExitFeeAmt := totalLongShares * longPrice * takerFees[pos.LongLeg.Exchange] / 100
+	shortExitFeeAmt := totalShortShares * shortPrice * takerFees[pos.ShortLeg.Exchange] / 100
+	longFeeUSD := longEntryFeeSum + longExitFeeAmt
+	shortFeeUSD := shortEntryFeeSum + shortExitFeeAmt
+
+	pos.LongLeg.ExitPrice = longPrice
+	pos.ShortLeg.ExitPrice = shortPrice
+
+	// Update exchange funds
+	t.mu.Lock()
+	if ef, ok := t.exchangeFunds[pos.LongLeg.Exchange]; ok {
+		ef.Balance -= longFeeUSD
+		ef.Balance += longPnlUSD
+		ef.TotalFee += longFeeUSD
+		ef.TotalPnl += longPnlUSD
+	}
+	if ef, ok := t.exchangeFunds[pos.ShortLeg.Exchange]; ok {
+		ef.Balance -= shortFeeUSD
+		ef.Balance += shortPnlUSD
+		ef.TotalFee += shortFeeUSD
+		ef.TotalPnl += shortPnlUSD
+	}
+	t.mu.Unlock()
+
+	// Build trade record
+	record := TradeRecord{
+		Coin:        pos.Coin,
+		Direction:   pos.Direction,
+		EntrySpread: pos.EntrySpread,
+		ExitSpread:  diffPct,
+		PnlPct:      netPnlPct,
+		PnlUSD:      2 * pos.AmountUSD * netPnlPct / 100,
+		Convergence: convergence,
+		Reason:      exitReason,
+		Duration:    elapsed.Round(time.Second).String(),
+		OpenedAt:    pos.StartedAt,
+		ClosedAt:    pos.ExitedAt,
+		ScaleLevels: pos.ScaleLevels,
+		AmountUSD:   pos.AmountUSD,
+		PnlLongUSD:  longPnlUSD,
+		PnlShortUSD: shortPnlUSD,
+		FeeLongUSD:  longFeeUSD,
+		FeeShortUSD: shortFeeUSD,
+	}
+
+	t.mu.Lock()
+	delete(t.positions, pos.Coin)
+	t.lastTradeTime[pos.Coin] = time.Now()
+	t.closedTrades = append(t.closedTrades, record)
+	t.realTradesDone++
+	t.mu.Unlock()
+
+	// Auto-stop after target real trades
+	if t.realTradesTarget > 0 && t.realTradesDone >= t.realTradesTarget {
+		log.Printf("[Trader] ✅ %d real trades completed — shutting down...", t.realTradesDone)
+		t.shuttingDown = true
+		select {
+		case t.StopCh <- struct{}{}:
+		default:
+		}
+	}
+
+	// Persist to DB
+	if t.db != nil && pos.DBTradeID > 0 {
+		now := time.Now()
+		status := "filled"
+
+		longOID, _ := t.db.SaveOrder(&db.OrderRecord{
+			TradeID: pos.DBTradeID, Leg: "long", Type: "exit",
+			Exchange: pos.LongLeg.Exchange, Side: "sell",
+			Price: &longPrice, Size: &totalLongShares,
+			Fee: &longExitFeeAmt, Status: &status, CreatedAt: now,
+		})
+		shortOID, _ := t.db.SaveOrder(&db.OrderRecord{
+			TradeID: pos.DBTradeID, Leg: "short", Type: "exit",
+			Exchange: pos.ShortLeg.Exchange, Side: "buy",
+			Price: &shortPrice, Size: &totalShortShares,
+			Fee: &shortExitFeeAmt, Status: &status, CreatedAt: now,
+		})
+		t.db.SaveSystemOrder(&db.SystemOrderRecord{
+			TradeID: pos.DBTradeID, Type: "exit", Status: "filled",
+			Spread: &diffPct,
+			LongPrice: &longPrice, ShortPrice: &shortPrice,
+			LongOrderID: &longOID, ShortOrderID: &shortOID,
+			CreatedAt: now,
+		})
+
+		feeEntrySum := longEntryFeeSum + shortEntryFeeSum
+		feeExitSum := longExitFeeAmt + shortExitFeeAmt
+		t.db.UpdateTradeStatus(pos.DBTradeID, &db.TradeRecord{
+			Status:      "closed",
+			ExitSpread:  &diffPct,
+			LongExit:    &longPrice,
+			ShortExit:   &shortPrice,
+			LongPnl:     &longPnlPct,
+			ShortPnl:    &shortPnlPct,
+			FeeEntry:    &feeEntrySum,
+			FeeExit:     &feeExitSum,
+			NetPnl:      &netPnlPct,
+			AmountUSD:   pos.AmountUSD,
+			ScaleCount:  pos.ScaleLevels,
+			ExitReason:  &exitReason,
+			Convergence: &convergence,
+			ClosedAt:    &now,
+			PnlLongUSD:  &longPnlUSD,
+			PnlShortUSD: &shortPnlUSD,
+			FeeLongUSD:  &longFeeUSD,
+			FeeShortUSD: &shortFeeUSD,
+		})
+	}
+
+	// SSE trade event
+	if t.OnTradeEvent != nil {
+		t.OnTradeEvent("trade_close", map[string]interface{}{
+			"coin":          pos.Coin,
+			"direction":     pos.Direction,
+			"entry_spread":  pos.EntrySpread,
+			"exit_spread":   diffPct,
+			"pnl_pct":       netPnlPct,
+			"pnl_usd":       record.PnlUSD,
+			"convergence":   convergence,
+			"reason":        exitReason,
+			"duration":      record.Duration,
+			"scale_levels":  pos.ScaleLevels,
+			"amount_usd":    pos.AmountUSD,
+			"long_pnl_usd":  record.PnlLongUSD,
+			"short_pnl_usd": record.PnlShortUSD,
+			"long_fee_usd":  record.FeeLongUSD,
+			"short_fee_usd": record.FeeShortUSD,
+		})
+	}
+}
+
 func (t *Trader) closeBothLegs(pos *ArbPosition) string {
 	errs := ""
 	if !pos.LongLeg.Closed {