fix(mobil-webb): krascha inte pa webben (Firebase-persistens)

getReactNativePersistence/AsyncStorage finns inte i webb-bygget (react-native-
web) och gav 'Cannot read properties of undefined (reading bind)' vid start.
Pa webben anvands nu Firebases standard-webblagring (getAuth), pa native
AsyncStorage som forr. Gor att webbversionen kan koras for felsokning.

apps/mobile/src/lib/auth-provider/firebase.ts

@@ -13,6 +13,7 @@ import {
 } from "firebase/auth";
 import * as fbAuth from "firebase/auth";
 import AsyncStorage from "@react-native-async-storage/async-storage";
+import { Platform } from "react-native";
 import type { AuthProvider, AuthUser, Unsubscribe } from "./types";
 
 /**
@@ -37,10 +38,16 @@ const getReactNativePersistence = (
  fbAuth as unknown as { getReactNativePersistence: (storage: unknown) => Persistence }
 ).getReactNativePersistence;
 
-// AsyncStorage-persistens så inloggningen överlever app-omstart.
+// Persistens så inloggningen överlever omstart. På webben (react-native-web)
+// finns INTE getReactNativePersistence/AsyncStorage – att anropa dem kraschar
+// hela appen vid start ("Cannot read properties of undefined (reading 'bind')").
+// Där använder vi Firebases standard-webblagring (getAuth), på native AsyncStorage.
 let auth: Auth;
 try {
- auth = initializeAuth(app, { persistence: getReactNativePersistence(AsyncStorage) });
+ auth =
+ Platform.OS === "web"
+ ? getAuth(app)
+ : initializeAuth(app, { persistence: getReactNativePersistence(AsyncStorage) });
 } catch {
  // initializeAuth kastar om den redan körts (Fast Refresh) – återanvänd instansen.
  auth = getAuth(app);