Stop a running desktop display manager during a live install

On a Pi OS Desktop image lightdm keeps display :0 until the next reboot,
so the kiosk X server failed with 'server already running'. Disabled
display managers are recorded and re-enabled by uninstall.sh.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

install.sh

@@ -243,11 +243,18 @@ for cmdline in /boot/firmware/cmdline.txt /boot/cmdline.txt; do
   fi
 done
 
-# A desktop display manager would fight over vt7.
+# A desktop display manager would fight over vt7 and display :0 (Pi OS Desktop images).
+# uninstall.sh re-enables the ones recorded here.
 for dm in lightdm.service gdm3.service sddm.service; do
   if systemctl is-enabled --quiet "$dm" 2>/dev/null; then
     warn "$dm wordt uitgeschakeld (de kiosk gebruikt een eigen minimale X-sessie)."
     systemctl disable "$dm" 2>/dev/null || true
+    grep -qx "$dm" /var/lib/voxip-kiosk/disabled-display-managers 2>/dev/null \
+      || echo "$dm" >> /var/lib/voxip-kiosk/disabled-display-managers
+  fi
+  if [[ $LIVE -eq 1 ]] && systemctl is-active --quiet "$dm" 2>/dev/null; then
+    warn "$dm wordt gestopt: de desktop op het scherm sluit nu af."
+    systemctl stop "$dm" || true
   fi
 done
 

uninstall.sh

@@ -20,6 +20,7 @@ UNITS=(voxip-kiosk-healthcheck.timer voxip-kiosk-healthcheck.service voxip-kiosk
        voxip-network-guard.service voxip-boot-import.service)
 
 PREVIOUS_TARGET="$(cat /var/lib/voxip-kiosk/previous-default-target 2>/dev/null || true)"
+mapfile -t DISABLED_DMS < <(cat /var/lib/voxip-kiosk/disabled-display-managers 2>/dev/null)
 
 echo "==> Services stoppen en verwijderen"
 systemctl stop voxip-network-rollback.timer 2>/dev/null || true
@@ -62,4 +63,5 @@ else
 fi
 
 if [[ -n $PREVIOUS_TARGET ]]; then systemctl set-default "$PREVIOUS_TARGET" >/dev/null 2>&1 || true; fi
+for dm in "${DISABLED_DMS[@]}"; do systemctl enable "$dm" >/dev/null 2>&1 || true; done
 echo "==> VoxIP Kiosk OS is verwijderd. Herstart de Raspberry Pi om de kiosk te stoppen."