feat: sync device settings after updates and improve remote connection features

- Add DeviceSettingsSync extension on Ref to centralize device provider
    updates after settings changes (sound, volume, language, timezone,
    battery, disable functions, alerts, pedometer, heart rate freq,
    location freq, background image)
  - Add photo capture countdown with Lottie animation in remote camera
  - Replace Image.network with Image.memory for photo display
  - Fix commands datasource to handle text/html responses (post<dynamic>)
  - Add typed error/success events to RemoteConnectionViewModel
  - Add background image active indicator and backgroundImageId to device settings
  - Change photos endpoint from /devices/identificator/:id/photos/files to /photos/files
  - Remove dead deviceId param from getBackgroundImage chain
  - Relax PictureEntity required fields to @Default for API compatibility
  - Fix LocationViewModel rebuild crash (ref.watch → ref.read)
  - Use .select() in RemoteCameraScreen for optimized rebuilds
  - Increase health measure countdown to 60s

packages/sf_localizations/assets/l10n/de.json

@@ -702,5 +702,9 @@
   "errorBatteryNightMode": "Der Nachtmodus konnte nicht aktualisiert werden",
   "timezoneUpdated": "Zeitzone aktualisiert",
   "errorTimezone": "Die Zeitzone konnte nicht aktualisiert werden",
-  "timezoneOther": "Andere Zeitzonen"
+  "timezoneOther": "Andere Zeitzonen",
+  "takingPhoto": "Foto wird aufgenommen...",
+  "errorTakePicture": "Fehler beim Fotografieren",
+  "errorFetchPhotos": "Fehler beim Abrufen der Fotos",
+  "errorCall": "Fehler beim Anrufen"
 }