also try wlopm when niri msg does not work, even if socket envvar exists

install.py

@@ -165,8 +165,8 @@ class HostConfig:
     temperature_path: str | None = None
     terminal: str = "alacritty"
     lock_cmd: str = "swaylock -c 000000"
-    display_on_cmd: str = "wlopm --on *"
+    display_on_cmd: str = "jdisplays on"
-    display_off_cmd: str = "wlopm --off *"
+    display_off_cmd: str = "jdisplays off"
     use_jump_host: bool = False
     inputs: list[InputConfig] = field(factory=list)
     outputs: list[OutputConfig] = field(factory=list)

templates/.config/niri/config.kdl.j2

@@ -192,6 +192,7 @@ spawn-at-startup "wireplumber"
 spawn-at-startup "waybar"
 spawn-at-startup "xwayland-satellite" ":12"
 spawn-at-startup "wpaperd"
+spawn-at-startup "swayidle"
 
 environment {
     DISPLAY ":12"

templates/bin/jdisplays

@@ -0,0 +1,10 @@
+#!/bin/sh
+
+case "$1" in
+    0|off) onoff=off ;;
+    1|on) onoff=on ;;
+    *) exit 1 ;;
+esac
+
+[ -e "$NIRI_SOCKET" ] && niri msg action power-$onoff-monitors \
+    || wlopm --$onoff '*'