- _showLocalNetworkDeniedSnackBar: wrap Process.run with unawaited()
and .catchError() so a rejected future (e.g. macOS sandbox refuses
fork, or 'open' is missing) cannot bubble into the Flutter zone
as an unhandled exception. The synchronous try/catch was a no-op
because Process.run only throws asynchronously.
- macos_permissions_service_test.dart: mirror the
triggerLocalNetworkPrompt error-handling test with one for
checkLocalNetworkAccess. Probe-path failures (NWConnection probe
cannot establish, or Swift side throws) must fall back to cached
state without crashing the caller.
Tests: 186 passed, 2 skipped. Dart analyze clean.