Make Omarchy shutdown grace timings configurable

[dpan]

Omarchy’s current reboot/logout/shutdown flow seems too aggressive for Chromium session persistence on my machine.

What I’m seeing:

• Chromium is set to Continue where you left off
• On normal browser exit, all windows restore correctly
• After a normal Omarchy reboot, Chromium usually restores only 1 of 3 windows

This suggests Chromium’s normal session state is getting cut off during shutdown, even though Omarchy already tries to close windows cleanly first.

Current behavior:

• omarchy-system-reboot, omarchy-system-shutdown, and omarchy-system-logout schedule the final action after sleep 2
• then close all windows
• then wait only sleep 1
• Omarchy also sets DefaultTimeoutStopSec=5s

Request:

• make these timings configurable via env vars instead of hardcoded values

For example:

OMARCHY_SHUTDOWN_ACTION_DELAY="${OMARCHY_SHUTDOWN_ACTION_DELAY:-2}"
OMARCHY_SHUTDOWN_APP_EXIT_GRACE="${OMARCHY_SHUTDOWN_APP_EXIT_GRACE:-1}"

and use those in:

• omarchy-system-reboot
• omarchy-system-shutdown
• omarchy-system-logout

That would let users tune shutdown behavior for apps like Chromium without editing Omarchy core files.