wiki:
https://wiki.archlinux.org/title/Bluetooth_(简体中文)
1. 确保蓝牙服务开机启动
systemctl enable bluetooth
2. 打开自动链接
配置文件：/etc/bluetooth/main.conf
# AutoEnable defines option to enable all controllers when they are found.
# This includes adapters present on start as well as adapters that are plugged
# in later on. Defaults to 'false'.
# AutoEnable 设置为true可以在设备发现时自动链接上
AutoEnable=true