App handles no-network state without crashing or blank screens

Apple explicitly tests offline behavior during review, and ISO 25010:2011 fault-tolerance requires graceful degradation under abnormal network conditions. An app that shows a blank white screen or a frozen loading spinner when launched without connectivity fails the most basic resilience test. TypeError: Network request failed propagating to a blank screen is indistinguishable to the reviewer from a crash. Apps that rely entirely on live API calls with no offline fallback and no timeout fail not just on review but in real-world use — poor connectivity is not an edge case.

Add a network state listener and set timeouts on all fetch calls.

// src/hooks/useNetworkStatus.ts
import NetInfo from '@react-native-community/netinfo';
import { useEffect, useState } from 'react';

export function useNetworkStatus() {
  const [isConnected, setIsConnected] = useState(true);
  useEffect(() => {
    return NetInfo.addEventListener(state => {
      setIsConnected(state.isConnected ?? true);
    });
  }, []);
  return isConnected;
}

Wrap all fetch calls with an AbortController that times out after 10–15 seconds. Show a clear "No internet connection" banner when offline with a retry button. Cache frequently accessed data with AsyncStorage or MMKV so the app has something useful to show.