feat(wallpapers): add image crop support and i18n strings

Adds per-image image-crop support with persistent settings.
Rendering adapts to crop mode, zoom and position per image.
Locales the UI strings and notifications; app name updated.

- Cropping workflow with per-image crop state and rendering
- Localizes strings and notifications for en and de
- Introduces set_image_crop command and its permission schema

plugins/android/src/main/java/WallpaperPlugin.kt

@@ -23,6 +23,15 @@ class GalleryArgs { var offset: Int = 0; var limit: Int = 48 }
 @InvokeArg
 class DeleteImageArgs { lateinit var id: String }
 
+@InvokeArg
+class ImageCropArgs {
+  lateinit var id: String
+  lateinit var mode: String
+  var zoom: Double = 1.0
+  var positionX: Double = 0.5
+  var positionY: Double = 0.5
+}
+
 @TauriPlugin
 class WallpaperPlugin(private val activity: Activity) : Plugin(activity) {
   private val io = Executors.newSingleThreadExecutor()
@@ -54,6 +63,15 @@ class WallpaperPlugin(private val activity: Activity) : Plugin(activity) {
     } catch (error: Exception) { invoke.reject(error.message ?: "Bild konnte nicht gelöscht werden") }
   }
 
+  @Command fun setImageCrop(invoke: Invoke) = io.execute {
+    try {
+      val args = invoke.parseArgs(ImageCropArgs::class.java)
+      val image = WallpaperStore.setCrop(activity, args.id, args.mode, args.zoom, args.positionX, args.positionY)
+        ?: throw IllegalArgumentException("Bild wurde nicht gefunden")
+      invoke.resolve(image)
+    } catch (error: Exception) { invoke.reject(error.message ?: "Bildausschnitt konnte nicht gespeichert werden") }
+  }
+
   @ActivityCallback
   fun selectedImages(invoke: Invoke, result: ActivityResult) {
     if (result.resultCode != Activity.RESULT_OK) { invoke.reject("Bildauswahl abgebrochen"); return }