fix: safe logout when firebase is not initialized

app/composables/useAuth.ts

@@ -42,10 +42,15 @@ export const useAuth = () => {
   }
 
   const logout = async () => {
-    const auth = getAuth()
+    try {
-    await signOut(auth)
+      const auth = getAuth()
-    token.value = null
+      await signOut(auth)
-    navigateTo('/login')
+    } catch (e) {
+      console.warn('[Firebase] Sign out failed or not initialized', e)
+    } finally {
+      token.value = null
+      navigateTo('/login')
+    }
   }
 
   const initAuth = () => {