Option to display Omarchy boot time to the user on login

[rfaile313]

Knowing how long it took to install omarchy is cool!

Let's provide users a simple option to see how fast omarchy boots every time they fire it up too:]

Omarchy auto-logs in, so the only thing you see between the splash logo and your desktop is the LUKS prompt. That gap is a natural place to show how long the boot took, and it turns out to be cheap to do from inside the initramfs.

I have it working as a small package here: https://github.com/rfaile313/omarchy-boottime

How it works:

• A mkinitcpio runtime hook, slotted just before encrypt, reads /proc/uptime, adds the firmware and loader time that Limine records in the LoaderTimeExecUSec EFI variable, and calls plymouth display-message.
• The build hook appends a few lines to the Omarchy Plymouth script as it is copied into the image, so the message is centred in the gap between the logo and the entry box. The stock theme already handles display-message, it just draws it top-left.
• A drop-in in /etc/mkinitcpio.conf.d/ inserts the hook.

Total footprint is about 40 lines and nothing runs after the prompt. The figure is power-on to prompt, which is the part of boot a user actually waits through.

Would this be welcome in Omarchy as an option? Two shapes I can see:

1. Ship the hook in omarchy-settings and expose omarchy toggle boot-time, which adds or removes the mkinitcpio drop-in and rebuilds.
2. Bake the message placement into the stock Plymouth script and ship the hook enabled by default, with the toggle only turning the message off.

Happy to open a PR for whichever fits. The only known limitation is that it needs the busybox initramfs with the encrypt hook, which is what Omarchy installs today.