fix: 4 bugfixes for production readiness

1. GetHLSize: add minimum size checks (prevent size=0 when price > amount)
2. executeEntry: orphan position warning when leg1 close also fails after leg2
3. checkExit: keep position as close_failed on failure, retryClose on each Tick
4. persistTrade: sync instead of goroutine (prevent data loss on exit)

exchange/hyperliquid_trade.go

@@ -178,21 +178,39 @@ func GetHLSize(coin string, amountUSD, price float64) string {
 	switch coin {
 	case "DOGE":
 		sz = math.Floor(sz) // step=1, szDecimals=0
+		if sz < 1 {
+			sz = 1
+		}
 		return fmt.Sprintf("%.0f", sz)
 	case "LINK":
 		sz = math.Floor(sz*10) / 10 // step=0.1, szDecimals=1
+		if sz < 0.1 {
+			sz = 0.1
+		}
 		return fmt.Sprintf("%.1f", sz)
 	case "ONDO":
 		sz = math.Floor(sz) // step=1, szDecimals=0
+		if sz < 1 {
+			sz = 1
+		}
 		return fmt.Sprintf("%.0f", sz)
 	case "OP":
 		sz = math.Floor(sz*10) / 10 // step=0.1, szDecimals=1
+		if sz < 0.1 {
+			sz = 0.1
+		}
 		return fmt.Sprintf("%.1f", sz)
 	case "WIF":
 		sz = math.Floor(sz) // step=1, szDecimals=0
+		if sz < 1 {
+			sz = 1
+		}
 		return fmt.Sprintf("%.0f", sz)
 	case "ARB":
 		sz = math.Floor(sz*10) / 10 // step=0.1, szDecimals=1
+		if sz < 0.1 {
+			sz = 0.1
+		}
 		return fmt.Sprintf("%.1f", sz)
 	default:
 		return fmt.Sprintf("%.4f", sz)

trader.go

@@ -228,6 +228,12 @@ func (t *Trader) Tick(store *PriceStore, notifier *Notifier) {
 		}
 		diffPct := (highP - lowP) / lowP * 100
 
+		// Retry close for positions that failed to close on previous attempt
+		if pos.Status == "close_failed" {
+			t.retryClose(pos, bgP, hlP, notifier)
+			continue
+		}
+
 		// Check scale-in: if spread widened enough, add more
 		t.checkScaleIn(pos, bgP, hlP, diffPct, store)
 
@@ -355,7 +361,16 @@ func (t *Trader) executeEntry(opp *ArbOpportunity, store *PriceStore, notifier *
 	}
 	time.Sleep(300 * time.Millisecond)
 	if err := t.placeOrder(pos.ShortLeg, "sell", store); err != "" {
-		t.closeLeg(pos.LongLeg)
+		// Leg1 placed successfully, leg2 failed — try to close leg1
+		if closeErr := t.closeLeg(pos.LongLeg); closeErr != "" {
+			// CRITICAL: leg1 is still open on the exchange!
+			// Record the orphan so we don't silently lose tracking
+			pos.ErrorLog = fmt.Sprintf("ORPHAN: leg1 %s %s placed OK, leg2 %s %s failed (%s), leg1 close also failed (%s)",
+				pos.LongLeg.Exchange, pos.LongLeg.Side,
+				pos.ShortLeg.Exchange, pos.ShortLeg.Side,
+				err, closeErr)
+			log.Printf("[Trader] ⚠️  ORPHAN POSITION on %s: %s", pos.Coin, pos.ErrorLog)
+		}
 		t.cleanup(pos.Coin)
 		return false
 	}
@@ -521,6 +536,20 @@ func (t *Trader) checkExit(pos *ArbPosition, bgP, hlP, diffPct float64, notifier
 
 	closeErr := t.closeBothLegs(pos)
 
+	if closeErr != "" {
+		// Close failed — keep the position for retry on next Tick
+		pos.Status = "close_failed"
+		pos.ErrorLog = closeErr
+		pos.ExitedAt = time.Now()
+		log.Printf("[Trader] ❌ %s: Close failed: %s — will retry on next tick", pos.Coin, closeErr)
+		notifier.Send(fmt.Sprintf(
+			"<b>[平仓失败]</b>  %s/USDT  %s\n"+
+				"  状态: close_failed\n"+
+				"  错误: %s\n"+
+				"  下一轮将重试关掉剩余的腿\n", pos.Coin, pos.Direction, closeErr))
+		return
+	}
+
 	pos.RealizedPnl = netPnl
 	pos.ExitedAt = time.Now()
 	pos.Status = "closed"
@@ -549,7 +578,7 @@ func (t *Trader) checkExit(pos *ArbPosition, bgP, hlP, diffPct float64, notifier
 
 	// Persist to SQLite
 	if t.db != nil {
-		go t.persistTrade(pos, diffPct, convergenceLabel, exitReason, netPnl, longPnl, shortPnl, totalFees)
+		t.persistTrade(pos, diffPct, convergenceLabel, exitReason, netPnl, longPnl, shortPnl, totalFees)
 	}
 
 	msg := fmt.Sprintf(
@@ -570,9 +599,6 @@ func (t *Trader) checkExit(pos *ArbPosition, bgP, hlP, diffPct float64, notifier
 		shortPnl, pos.ShortLeg.Exchange, pos.ShortLeg.EntryPrice, shortCurrent,
 		totalFees, netPnl, exitReason,
 	)
-	if closeErr != "" {
-		msg += fmt.Sprintf("  平仓异常: %s\n", closeErr)
-	}
 	notifier.Send(msg)
 
 	// P3-4: real-time trade event push
@@ -658,6 +684,40 @@ func (t *Trader) closeLeg(leg *PositionLeg) string {
 	return ""
 }
 
+// retryClose retries closing a position that previously failed.
+// Only closes legs not already marked Closed. Notifies periodically.
+func (t *Trader) retryClose(pos *ArbPosition, bgP, hlP float64, notifier *Notifier) {
+	log.Printf("[Trader] %s: Retrying close (previous err: %s)", pos.Coin, pos.ErrorLog)
+
+	closeErr := t.closeBothLegs(pos)
+	if closeErr == "" {
+		// All legs finally closed — mark as done
+		pos.Status = "closed"
+		pos.ExitedAt = time.Now()
+		t.mu.Lock()
+		delete(t.positions, pos.Coin)
+		t.lastTradeTime[pos.Coin] = time.Now()
+		t.mu.Unlock()
+		notifier.Send(fmt.Sprintf(
+			"<b>[平仓重试成功]</b>  %s/USDT  %s\n"+
+				"  之前失败: %s\n"+
+				"  已成功关掉所有腿\n", pos.Coin, pos.Direction, pos.ErrorLog))
+		return
+	}
+
+	// Still failing — update log and notify periodically
+	pos.ErrorLog = closeErr
+	log.Printf("[Trader] ❌ %s: Retry close still failing: %s", pos.Coin, closeErr)
+	if time.Since(pos.ExitedAt) > 30*time.Second {
+		notifier.Send(fmt.Sprintf(
+			"<b>[平仓仍失败]</b>  %s/USDT  %s\n"+
+				"  已重试 %s, 仍失败: %s\n"+
+				"  请手动检查交易所\n", pos.Coin, pos.Direction,
+			time.Since(pos.ExitedAt).Round(time.Second).String(), closeErr))
+		pos.ExitedAt = time.Now()
+	}
+}
+
 // placeOrderAt places an order at a specified price (used for scale-in, Issue #2).
 // Unlike placeOrder, this doesn't modify the leg's EntryPrice — it places
 // an additional order at the current market price for the same trade amount.