Remove dead code

shell/plugins/background/manifest.json

@@ -5,7 +5,10 @@
   "version": "1.0.0",
   "author": "Omarchy",
   "description": "Desktop background renderer with click handling and transitions",
-  "kinds": ["service"],
-  "activation": "startup",
-  "entryPoints": { "service": "Background.qml" }
+  "kinds": [
+    "service"
+  ],
+  "entryPoints": {
+    "service": "Background.qml"
+  }
 }