fix: 移除多余的netPnl和反转检查, 收敛即退出(0.02%)

trader.go

@@ -534,19 +534,12 @@ func (t *Trader) checkExit(pos *ArbPosition, bgP, hlP, diffPct float64, notifier
 		exitReason = "利润止盈"
 	}
 
-	// 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 {
+	// Convergence exit: spread narrowed to ≤ 0.02% (includes reversal)
+	if diffPct <= 0.02 {
 		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