NetworkReachability class final

The central entry point for the Network Reachability library.

This service provides a robust, high-level API for monitoring and validating network connectivity. It handles complex logic such as request coalescing, caching, and resilience patterns like the circuit breaker.

Core Features:

• Manual Checks: Trigger precise network probes using check.
• Security Guard: Protect sensitive operations from insecure networks using guard.
• Real-time Monitoring: Listen to connectivity changes via onStatusChange.
• Lifecycle Awareness: Automatically manages battery efficiency by pausing background checks when the app is minimized.

Example Usage:

 1. Initialize at app startup
await NetworkReachability.init();

 2. Perform a one-time check
final report = await NetworkReachability.instance.check();
print('Connected: ${report.status.isConnected}, Quality: ${report.status.quality}');

 3. Protect an API call
try {
  await NetworkReachability.instance.guard(
    action: () => myApi.fetchData(),
    minQuality: ConnectionQuality.good,
  );
} on NetworkReachabilityException catch (e) {
  print('Operation blocked: ${e.message}');
}