Resolve all lints and deprecation warnings

lib/services/health_service.dart

@@ -1,6 +1,4 @@
 import 'package:health/health.dart';
-import 'package:collection/collection.dart';
-import 'dart:io';
 import 'package:flutter/foundation.dart';
 import '../models/cycle_entry.dart';
 
@@ -10,14 +8,12 @@ class HealthService {
   HealthService._internal();
 
   final Health _health = Health();
-  
+
   // ignore: unused_field
   List<HealthDataType> _requestedTypes = [];
 
-  // TODO: Fix HealthDataType for menstruation in newer health package versions
   static const List<HealthDataType> _menstruationDataTypes = [
-     // HealthDataType.MENSTRUATION - Not found in recent versions?
-     HealthDataType.STEPS, // Placeholder to avoid compile error
+    HealthDataType.MENSTRUATION_FLOW,
   ];
 
   Future<bool> requestAuthorization(List<HealthDataType> types) async {
@@ -37,9 +33,10 @@ class HealthService {
 
   Future<bool> writeMenstruationData(List<CycleEntry> entries) async {
     // This feature is currently disabled until compatible HealthDataType is identified
-    debugPrint("writeMenstruationData: Currently disabled due to package version incompatibility.");
+    debugPrint(
+        "writeMenstruationData: Currently disabled due to package version incompatibility.");
     return false;
-    
+
     /*
     final periodEntries = entries.where((entry) => entry.isPeriodDay).toList();