Fix firebase config crash with dummy fallbacks

firebase.ts

@@ -3,13 +3,13 @@ import { getAuth, GoogleAuthProvider, signInWithPopup, signOut } from 'firebase/
 import { getFirestore, doc, getDocFromServer } from 'firebase/firestore';
 
 const firebaseConfig = {
-  apiKey: import.meta.env.VITE_FIREBASE_API_KEY,
-  authDomain: import.meta.env.VITE_FIREBASE_AUTH_DOMAIN,
-  projectId: import.meta.env.VITE_FIREBASE_PROJECT_ID,
-  storageBucket: import.meta.env.VITE_FIREBASE_STORAGE_BUCKET,
-  messagingSenderId: import.meta.env.VITE_FIREBASE_MESSAGING_SENDER_ID,
-  appId: import.meta.env.VITE_FIREBASE_APP_ID,
-  measurementId: import.meta.env.VITE_FIREBASE_MEASUREMENT_ID
+  apiKey: import.meta.env.VITE_FIREBASE_API_KEY || "dummy-api-key",
+  authDomain: import.meta.env.VITE_FIREBASE_AUTH_DOMAIN || "dummy-auth-domain",
+  projectId: import.meta.env.VITE_FIREBASE_PROJECT_ID || "dummy-project-id",
+  storageBucket: import.meta.env.VITE_FIREBASE_STORAGE_BUCKET || "dummy-storage-bucket",
+  messagingSenderId: import.meta.env.VITE_FIREBASE_MESSAGING_SENDER_ID || "dummy-sender-id",
+  appId: import.meta.env.VITE_FIREBASE_APP_ID || "dummy-app-id",
+  measurementId: import.meta.env.VITE_FIREBASE_MEASUREMENT_ID || "dummy-measurement-id"
 };
 
 // Check if Firebase config is complete to avoid "invalid-api-key" error