refactor(branding): rename project to LockScreenWallpaper across repo

Standardize branding by renaming Wechselbild to LockScreenWallpaper.
This updates UI strings, configs, and plugin metadata for consistency.

- Rename branding across UI, docs, and config in the repo
- Update Android UI strings and notification titles to LockScreenWallpaper

package-lock.json

@@ -1,11 +1,11 @@
 {
-  "name": "wechselbild",
+  "name": "lockscreenwallpaper",
   "version": "0.1.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
-      "name": "wechselbild",
+      "name": "lockscreenwallpaper",
       "version": "0.1.0",
       "dependencies": {
         "@tauri-apps/api": "^2.8.0",