Refactor note handling to use epoch time and improve utility functions for settings management

lib/utils.dart

@@ -0,0 +1,39 @@
+import 'package:journaler/meilisearch.dart';
+
+Future<double> getVolume() async {
+  try {
+    final volumeStr = await getSetting('notificationVolume');
+    return double.tryParse(volumeStr ?? '0.7') ?? 0.7;
+  } catch (e) {
+    return 0.7;
+  }
+}
+
+Future<void> setVolume(double volume) async {
+  await setSetting('notificationVolume', volume.toString());
+}
+
+Future<Duration> getPopupInterval() async {
+  try {
+    final intervalStr = await getSetting('popupIntervalMinutes');
+    return Duration(minutes: int.tryParse(intervalStr ?? '10') ?? 10);
+  } catch (e) {
+    return Duration(minutes: 10);
+  }
+}
+
+Future<void> setPopupInterval(Duration interval) async {
+  await setSetting('popupIntervalMinutes', interval.inMinutes.toString());
+}
+
+Future<String> getNotificationSound() async {
+  try {
+    return await getSetting('notificationSound') ?? 'MeetTheSniper.mp3';
+  } catch (e) {
+    return 'MeetTheSniper.mp3';
+  }
+}
+
+Future<void> setNotificationSound(String sound) async {
+  await setSetting('notificationSound', sound);
+}