Use capacitor preferences package instead of localStorage

src/app/util/theme.ts

@@ -1,7 +1,8 @@
-import {synced, localStorageProvider} from "@welshman/store"
+import {preferencesStorageProvider} from "@src/lib/storage"
+import {synced} from "@welshman/store"
 
 export const theme = synced({
   key: "theme",
   defaultValue: "dark",
-  storage: localStorageProvider,
+  storage: preferencesStorageProvider,
 })