fix: 收敛退出放宽到0.02%+净利为正, 恢复到0.02%即退不亏钱

trader.go

@@ -534,12 +534,19 @@ func (t *Trader) checkExit(pos *ArbPosition, bgP, hlP, diffPct float64, notifier
 		exitReason = "利润止盈"
 	}
 
-	// Exit when spread converges to zero or reverses (prices same or flipped)
-	if diffPct <= 0 {
+	// Convergence exit: spread narrowed significantly and we're profitable
+	// Prevents positions from sitting at near-zero spread waiting for timeout
+	if diffPct <= 0.02 && netPnl > 0 {
 		shouldExit = true
 		exitReason = "价差收敛止盈"
 	}
 
+	// Emergency reversal: spread flipped negative — cut losses
+	if diffPct < 0 {
+		shouldExit = true
+		exitReason = "价差反转平仓"
+	}
+
 	// Timeout: configured max hold time
 	if elapsed > t.cfg.PositionTimeout {
 		shouldExit = true