Display/GUI watchdog for the "backlight on, no picture" failure

On PoE sites the MIPI-DSI panel can lose its init on a supply dip while the
RK3566 keeps running; the UI may also hang or exit. Three layers:

- hardware watchdog: systemd RuntimeWatchdogSec=20s (system.conf.d)
- GUI: SdWatchdog pings systemd per swapped frame (WATCHDOG_USEC=30s, enabled
  by the binary so older versions run under the same unit) and writes
  run/qt.frame; buttontask.service gets Restart=always, NotifyAccess=main,
  TimeoutAbortSec=10s
- bt-displaywatch (root, buttontask-displaywatch.service): kernel DRM/DSI
  timeouts, eth link down->up (PoE dip hint), stale UI frames, restart storms
  -> panel re-init (stop UI, fb0 blank 4->0, start UI), repeated -> reboot
  (max 3/day, never during OTA); incident log in /var/log/buttontask/

Manual recovery: hold one finger 10 s in the bottom-left corner (panels are
single-touch). Delivered by OTA via bt-update sync_system; the web service
runs `bt-update sync-system` at start for devices updated by an older
bt-update.

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

winDeployScripts/device-install.sh

@@ -116,7 +116,8 @@ fi
 # 4. Привилегированные хелперы + sudoers
 # ---------------------------------------------------------------------------
 for s in bt-netconfig bt-netconfig-boot bt-update bt-service \
-         bt-settime bt-reboot bt-access bt-brightness bt-set-master; do
+         bt-settime bt-reboot bt-access bt-brightness bt-set-master \
+         bt-displaywatch; do
   [ -f "$BUNDLE_DIR/scripts/$s" ] || die "нет scripts/$s в бандле"
   install -m0755 "$BUNDLE_DIR/scripts/$s" "$ROOT/scripts/"
 done
@@ -168,6 +169,14 @@ if [ -f "$BT_OVR" ]; then
   sed 's/\r$//' "$BT_OVR" > /etc/systemd/system/bluetooth.service.d/override.conf
   log "bluetooth.service: Restart=always"
 fi
+# аппаратный вотчдог (/dev/watchdog): зависло ядро -> плата перезагрузится сама
+WD_CONF="$BUNDLE_DIR/webconfig/system.conf.d/buttontask-watchdog.conf"
+if [ -f "$WD_CONF" ]; then
+  install -d /etc/systemd/system.conf.d
+  sed 's/\r$//' "$WD_CONF" > /etc/systemd/system.conf.d/buttontask-watchdog.conf
+  systemctl daemon-reexec || warn "daemon-reexec не удался — вотчдог включится после ребута"
+  log "аппаратный вотчдог: RuntimeWatchdogSec из buttontask-watchdog.conf"
+fi
 
 # ---------------------------------------------------------------------------
 # 8. Авто-детект тачскрина -> override.conf (eventN зависит от платы)
@@ -209,6 +218,8 @@ systemctl enable buttontask buttontask-web buttontask-network buttontask-collect
   systemctl enable buttontask buttontask-web buttontask-collector >/dev/null 2>&1 || \
   systemctl enable buttontask buttontask-web >/dev/null 2>&1 || \
   die "не удалось включить сервисы (проверьте имена юнитов)"
+# вотчдог дисплея/GUI (переинициализация DSI-панели, эскалация в ребут)
+systemctl enable buttontask-displaywatch >/dev/null 2>&1 || warn "не удалось enable buttontask-displaywatch"
 
 # применить сеть сразу (не ждать ребута), если есть сохранённый профиль
 if [ -f "$ROOT/config/network.json" ] && [ -x "$ROOT/scripts/bt-netconfig-boot" ]; then

winDeployScripts/make-adb-bundle.ps1

@@ -48,6 +48,7 @@ $scriptsSrc = Join-Path $web 'scripts'
 $needScripts = @(
   'bt-netconfig', 'bt-netconfig-boot', 'bt-update', 'bt-service',
   'bt-settime', 'bt-reboot', 'bt-access', 'bt-brightness', 'bt-set-master',
+  'bt-displaywatch',
   'buttontask.sudoers'
 )
 foreach ($s in $needScripts) {
@@ -180,7 +181,7 @@ $fix = @()
 $fix += Get-ChildItem (Join-Path $stage 'scripts') -File
 $fix += Get-ChildItem (Join-Path $stage 'systemd')  -File
 $fix += Get-Item      (Join-Path $stage 'device-install.sh')
-$fix += @(Get-ChildItem (Join-Path $stage 'webconfig') -Recurse -File -Include 'bt-*', '*.sh', '*.service', '*.sudoers', 'override.conf*')
+$fix += @(Get-ChildItem (Join-Path $stage 'webconfig') -Recurse -File -Include 'bt-*', '*.sh', '*.service', '*.sudoers', 'override.conf*', '*.conf')
 $fix | Sort-Object FullName -Unique | ForEach-Object { ConvertTo-Lf $_.FullName }
 
 Log "пакую архив"