Provide option to check for power

[ianmmyers]

I would like to see an option in which Setup Manager checks to see if the device is plugged in and won't proceed until power is provided. This won't prevent cases where power is removed in the middle of setup but would serve as a reminder to plug it in at the start, to ensure the device completes the process without running out of battery.

[scriptingosx]

Setup Manager already monitors the battery. You can hit command-B while the Setup Manager window is active to show the battery status in the Setup Manager window. This is somewhat redundant unless you have a background set.

When the battery drops below 20% a big red warning window will appear, reminding the user or tech to plug in the device. Apple Silicon devices usually last 1-2 hours or more on 20% battery. This is also the threshold at which Apple's software update starts warning.

(I temporarily raised the warning threshold to create this screen shot, the built-in threshold is 20%)