优化sshd的客户端, 添加"cls"清屏指令支持

sshd/client/client.go

@@ -188,7 +188,7 @@ func term(pingState *atomic.Bool) {
 			break
 		}
 
-		if input == "clear" {
+		if input == "cls" || input == "clear" {
 			clearScreen()
 			continue
 		}