feat: export auth from firebase

src/utils/firebaseConfig.js

@@ -1,5 +1,12 @@
 // Import the functions you need from the SDKs you need
 import { initializeApp } from 'firebase/app';
+import { getAuth } from 'firebase/auth';
+import {
+  CACHE_SIZE_UNLIMITED,
+  initializeFirestore,
+  persistentLocalCache,
+  persistentSingleTabManager,
+} from 'firebase/firestore';
 // TODO: Add SDKs for Firebase products that you want to use
 // https://firebase.google.com/docs/web/setup#available-libraries
 
@@ -17,6 +24,13 @@ const firebaseConfig = {
 
 // Initialize Firebase
 const app = initializeApp(firebaseConfig);
-const db = getFirestore(app);
 
-export { db };
+// Enable IndexedDB persistence with single-tab manager
+export const db = initializeFirestore(app, {
+  localCache: persistentLocalCache({
+    tabManager: persistentSingleTabManager(),
+    cacheSizeBytes: CACHE_SIZE_UNLIMITED,
+  }),
+});
+
+export const auth = getAuth(app);