claude refactorings, flutter best practices, platform dependent changes, general cleanup

lib/api/webuntis/queries/authenticate/authenticate.dart

@@ -2,9 +2,9 @@ import 'dart:async';
 import 'dart:convert';
 
 import '../../../../model/account_data.dart';
-import '../../webuntisApi.dart';
-import 'authenticateParams.dart';
-import 'authenticateResponse.dart';
+import '../../webuntis_api.dart';
+import 'authenticate_params.dart';
+import 'authenticate_response.dart';
 
 class Authenticate extends WebuntisApi {
   AuthenticateParams param;
@@ -15,18 +15,19 @@ class Authenticate extends WebuntisApi {
   Future<AuthenticateResponse> run() async {
     awaitingResponse = true;
     try {
-      var rawAnswer = await query(this);
-      AuthenticateResponse response = finalize(AuthenticateResponse.fromJson(jsonDecode(rawAnswer)['result']));
+      final rawAnswer = await query(this);
+      final decoded = jsonDecode(rawAnswer) as Map<String, dynamic>;
+      final response = finalize(AuthenticateResponse.fromJson(decoded['result'] as Map<String, dynamic>));
       _lastResponse = response;
-      if(!awaitedResponse.isCompleted) awaitedResponse.complete();
+      if (!awaitedResponse.isCompleted) awaitedResponse.complete();
       return response;
     } catch (e) {
       // Surface the error to anyone waiting on the current completer, then
       // install a fresh one so a future attempt can succeed. Without this,
       // any later call to getSession() would hang forever on a completer
       // that is already settled with no listeners (or never settles at all).
-      if(!awaitedResponse.isCompleted) awaitedResponse.completeError(e);
-      awaitedResponse = Completer();
+      if (!awaitedResponse.isCompleted) awaitedResponse.completeError(e);
+      awaitedResponse = Completer<void>();
       rethrow;
     } finally {
       awaitingResponse = false;
@@ -34,7 +35,7 @@ class Authenticate extends WebuntisApi {
   }
 
   static bool awaitingResponse = false;
-  static Completer awaitedResponse = Completer();
+  static Completer<void> awaitedResponse = Completer<void>();
   static AuthenticateResponse? _lastResponse;
 
   static Future<void> createSession() async {