fix: Keep Waybar alive when switching themes from a bar module (#96)

Switching Dark/Light from the Waybar module left the bar gone until the
next login.

DarkLight.sh is wired to a Waybar module on-click, so it runs inside
waybar.service's cgroup. Its cleanup loop kills waybar, systemd tears down
the whole unit, and every process in that cgroup goes with it - DarkLight.sh
included, before it ever reaches Refresh.sh. Nothing is left to start the
replacement bar. Refresh.sh had the same problem on its own: it killed
waybar and relaunched it from a shell that had just been torn down.

Drop waybar from the DarkLight.sh cleanup loop and let Refresh.sh own the
restart, run as a transient systemd-run --user unit so it sits outside the
caller's cgroup and survives the teardown. Fall back to setsid where
systemd-run is unavailable.

Detect systemd management via the unit's LoadState instead of is-enabled.
WaybarStartup.sh starts the unit on demand and leaves it disabled, so
is-enabled reports "disabled" for setups that are in fact systemd-managed.

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

2 files changed, 35 insertions, 27 deletions

diff --git a/config/hypr/scripts/DarkLight.sh b/config/hypr/scripts/DarkLight.sh
index 913099fc..5bad2af8 100755
--- a/config/hypr/scripts/DarkLight.sh
+++ b/config/hypr/scripts/DarkLight.sh
@@ -354,7 +354,11 @@ ${SCRIPTSDIR}/WallustSwww.sh
 if [ "$no_restart" -eq 0 ]; then
     sleep 2
     # kill process
-    for pid1 in waybar rofi swaync ags swaybg; do
+    # NOTE: waybar is deliberately excluded here. This script is usually launched from a
+    # waybar module on-click, so it lives in waybar.service's cgroup. Killing waybar makes
+    # systemd tear down the whole unit, taking this script with it before Refresh.sh runs.
+    # Refresh.sh restarts waybar detached from that cgroup instead.
+    for pid1 in rofi swaync ags swaybg; do
         killall "$pid1"
     done
     sleep 1
diff --git a/config/hypr/scripts/Refresh.sh b/config/hypr/scripts/Refresh.sh
index 79495d0f..98fbcb18 100755
--- a/config/hypr/scripts/Refresh.sh
+++ b/config/hypr/scripts/Refresh.sh
@@ -47,38 +47,42 @@ for pid in $(pidof rofi swaync ags swaybg); do
   sleep 0.1
 done
 
-# Restart waybar once (works with systemd user unit or manual launch setups)
-restart_waybar() {
-  local manage_with_systemd=0
+# Does a waybar.service user unit exist? Checks LoadState rather than is-enabled: the
+# unit is usually started on demand by WaybarStartup.sh and left disabled, so is-enabled
+# reports "disabled" for a setup that is nevertheless systemd-managed.
+waybar_unit_exists() {
+  local load_state
+  command -v systemctl >/dev/null 2>&1 || return 1
+  load_state="$(systemctl --user show waybar.service --property=LoadState --value 2>/dev/null || true)"
+  [ -n "$load_state" ] && [ "$load_state" != "not-found" ]
+}
 
-  if command -v systemctl >/dev/null 2>&1; then
-    if systemctl --user --quiet is-active graphical-session.target 2>/dev/null || systemctl --user --quiet is-active wayland-session@*.target 2>/dev/null; then
-      if systemctl --user --quiet is-active waybar.service 2>/dev/null || systemctl --user --quiet is-enabled waybar.service 2>/dev/null; then
-        manage_with_systemd=1
-      fi
-    fi
-  fi
+# Restart waybar once, DETACHED from this script's cgroup.
+# This script is typically invoked from a waybar module on-click (e.g. DarkLight.sh), so
+# it runs inside waybar.service's cgroup. Killing waybar from in there makes systemd tear
+# down the whole unit and every process in it - this script included - so the replacement
+# waybar never gets launched and the bar stays gone. Running the restart as a transient
+# systemd unit puts it outside that cgroup, where it survives the teardown.
+restart_waybar() {
+  local restart_cmd
 
-  if [ "$manage_with_systemd" -eq 1 ]; then
-    systemctl --user stop waybar.service >/dev/null 2>&1 || true
+  if waybar_unit_exists; then
+    restart_cmd='pkill -x waybar; pkill -x .waybar-wrapped; sleep 0.3; systemctl --user reset-failed waybar.service >/dev/null 2>&1; exec systemctl --user restart waybar.service'
+  else
+    restart_cmd='pkill -x waybar; pkill -x .waybar-wrapped; sleep 0.3; exec waybar'
   fi
 
-  pkill -x waybar >/dev/null 2>&1 || true
-  pkill -x '.waybar-wrapped' >/dev/null 2>&1 || true
-  sleep 0.2
-  if pgrep -x waybar >/dev/null 2>&1 || pgrep -x '.waybar-wrapped' >/dev/null 2>&1; then
-    pkill -9 -x waybar >/dev/null 2>&1 || true
-    pkill -9 -x '.waybar-wrapped' >/dev/null 2>&1 || true
+  if command -v systemd-run >/dev/null 2>&1 &&
+    systemd-run --user --collect --quiet --no-block \
+      --setenv=WAYLAND_DISPLAY="${WAYLAND_DISPLAY:-}" \
+      --setenv=XDG_RUNTIME_DIR="${XDG_RUNTIME_DIR:-/run/user/$(id -u)}" \
+      --setenv=HYPRLAND_INSTANCE_SIGNATURE="${HYPRLAND_INSTANCE_SIGNATURE:-}" \
+      /bin/bash -c "$restart_cmd" >/dev/null 2>&1; then
+    return 0
   fi
-  sleep 0.2
 
-  if [ "$manage_with_systemd" -eq 1 ]; then
-    if ! systemctl --user start waybar.service >/dev/null 2>&1; then
-      waybar >/dev/null 2>&1 &
-    fi
-  else
-    waybar >/dev/null 2>&1 &
-  fi
+  # Fallback when systemd-run is unavailable: detach as far as we can.
+  setsid /bin/bash -c "$restart_cmd" >/dev/null 2>&1 &
 }
 
 restart_waybar