main, fix cert issues on older versions of Android (before Let's Encrypt existed).

lib/main.dart

@@ -12,6 +12,11 @@ import 'package:alarm/alarm.dart';
 
 import 'dart:convert';
 
+// For trusting Let's Encrypt on older devices (SDK 24, Android 7)
+//import 'dart:io';
+//import 'package:http/http.dart' as http;
+import 'package:flutter/services.dart' show rootBundle;
+
 /// TBD:
 /// - Add other languages (Spanish, Croatian)
 /// v1.1.0
@@ -22,6 +27,14 @@ import 'dart:convert';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
+
+  final certData = await rootBundle.load(
+    'media/certs/open-meteo-com_isrg-root-x1.pem',
+  );
+  SecurityContext.defaultContext.setTrustedCertificatesBytes(
+    certData.buffer.asUint8List(),
+  );
+
   tz.initializeTimeZones();
   await Alarm.init();
   runApp(const SunsetAlarmApp());