feat(wallpaper): extend commands with gallery, delete image, and crop

The plugin now exposes gallery retrieval, image deletion and image crop
across Android, desktop and mobile. The Rust core and Android
bridge are wired to handle these commands, updating state as needed.

- Add gallery, delete_image, and set_image_crop commands
- across Android, desktop and mobile.
- Update permissions, defaults, and schema to enable new commands.

plugins/build.rs

@@ -1,8 +1,16 @@
-const COMMANDS: &[&str] = &["get_state", "select_images", "set_setting", "next_wallpaper"];
+const COMMANDS: &[&str] = &[
+    "get_state",
+    "get_gallery",
+    "select_images",
+    "delete_image",
+    "set_image_crop",
+    "set_setting",
+    "next_wallpaper",
+];
 
 fn main() {
-  tauri_plugin::Builder::new(COMMANDS)
-    .android_path("android")
-    .ios_path("ios")
-    .build();
+    tauri_plugin::Builder::new(COMMANDS)
+        .android_path("android")
+        .ios_path("ios")
+        .build();
 }