services: Move flashfocus to systemd service

Removed manual initialization of flashfocus from xinitrc, enabled the
service in systemd.

Changed the restart timer to 5 seconds, to mirror other X-dependent user
services to circumvent systemd being too eager to start the service
before X is ready on booting.

X/.config/xresources/xinitrc

@@ -56,8 +56,6 @@ type xcape >/dev/null 2>&1 && xcape -e 'Control_L=Escape' -t 500
 type unclutter >/dev/null 2>&1 && unclutter &
 # picom is the maintained version of desktop compositor compton
 type picom >/dev/null 2>&1 && picom &
-# flashfocus 'flashes' windows as they gain focus
-type flashfocus >/dev/null 3>&1 && flashfocus --flash-lone-windows never &
 
 # if sxhkd - the key-binding daemon is installed, start it up
 type sxhkd >/dev/null 2>&1 && sxhkd-piped &

services/.config/systemd/user/flashfocus.service.d/override.conf

@@ -0,0 +1,2 @@
+[Service]
+RestartSec=5

services/.config/systemd/user/graphical-session.target.wants/flashfocus.service

@@ -0,0 +1 @@
+/usr/lib/systemd/user/flashfocus.service