Make setup ISO-only

Remove legacy online installer entrypoints, collapse migrations for 4.0, and move setup responsibilities into target-side system, hardware, and user commands.

bin/omarchy-system-sleep-monitor

@@ -7,11 +7,13 @@
 monitor_command='exec dbus-monitor --system "type='\''signal'\'',sender='\''org.freedesktop.login1'\'',interface='\''org.freedesktop.login1.Manager'\'',member='\''PrepareForSleep'\''"'
 
 consume_sleep_events() {
-  local line
+  local line sleep_lock
+  sleep_lock=$(command -v omarchy-system-sleep-lock || true)
+  sleep_lock=${sleep_lock:-/usr/bin/omarchy-system-sleep-lock}
 
   while IFS= read -r line; do
     if [[ $line == *"boolean true"* ]]; then
-      "$OMARCHY_PATH/bin/omarchy-system-sleep-lock"
+      "$sleep_lock"
       exit 0
     fi
   done
@@ -22,9 +24,12 @@ if [[ ${1:-} == "--consume" ]]; then
   exit 0
 fi
 
+sleep_monitor=$(command -v omarchy-system-sleep-monitor || true)
+sleep_monitor=${sleep_monitor:-/usr/bin/omarchy-system-sleep-monitor}
+
 exec systemd-inhibit \
   --what=sleep \
   --mode=delay \
   --who=Omarchy \
   --why="Lock screen before suspend" \
-  bash -lc "$monitor_command | \"$OMARCHY_PATH/bin/omarchy-system-sleep-monitor\" --consume"
+  bash -lc "$monitor_command | \"$sleep_monitor\" --consume"