feat(wallpaper): add apply_wallpaper workflow and rotation worker

Adds a new apply_wallpaper command and its plumbing across
desktop, mobile, and Android. A WorkManager-based rotation
worker handles applying wallpapers in the background. Wallpaper
state now tracks currentId and imageIds for precise control.

- Introduced apply_wallpaper command across desktop, mobile and Android
- Added WorkManager-based rotation worker to apply wallpapers in the
  background
- Extended wallpaper state with currentId and imageIds and updated schemas/permissions

plugins/src/lib.rs

@@ -46,6 +46,7 @@ pub fn init<R: Runtime>() -> TauriPlugin<R> {
             commands::set_setting,
             commands::set_interval,
             commands::next_wallpaper,
+            commands::apply_wallpaper,
             commands::get_immich_connection,
             commands::connect_immich,
             commands::disconnect_immich,