refactor: Enable more strict lints

lib/widgets/adaptive_dialogs/public_room_dialog.dart

@@ -23,7 +23,7 @@ class PublicRoomDialog extends StatelessWidget {
 
   const PublicRoomDialog({super.key, this.roomAlias, this.chunk, this.via});
 
-  void _joinRoom(BuildContext context) async {
+  Future<void> _joinRoom(BuildContext context) async {
     final client = Matrix.of(context).client;
     final chunk = this.chunk;
     final knock = chunk?.joinRule == 'knock';

lib/widgets/app_lock.dart

@@ -41,7 +41,7 @@ class AppLock extends State<AppLockWidget> with WidgetsBindingObserver {
     WidgetsBinding.instance.addPostFrameCallback(_checkLoggedIn);
   }
 
-  void _checkLoggedIn(_) async {
+  Future<void> _checkLoggedIn(_) async {
     if (widget.clients.any((client) => client.isLogged())) return;
 
     await changePincode(null);

lib/widgets/config_viewer.dart

@@ -16,7 +16,7 @@ class ConfigViewer extends StatefulWidget {
 }
 
 class _ConfigViewerState extends State<ConfigViewer> {
-  void _changeSetting(
+  Future<void> _changeSetting(
     AppSettings appSetting,
     SharedPreferences store,
     String initialValue,

lib/widgets/local_notifications_extension.dart

@@ -22,7 +22,7 @@ extension LocalNotificationsExtension on MatrixState {
     ..src = 'assets/assets/sounds/notification.ogg'
     ..load();
 
-  void showLocalNotification(Event event) async {
+  Future<void> showLocalNotification(Event event) async {
     final roomId = event.room.id;
     if (activeRoomId == roomId) {
       if (WidgetsBinding.instance.lifecycleState == AppLifecycleState.resumed) {

lib/widgets/lock_screen.dart

@@ -20,7 +20,7 @@ class _LockScreenState extends State<LockScreen> {
   bool _inputBlocked = false;
   final TextEditingController _textEditingController = TextEditingController();
 
-  void tryUnlock(String text) async {
+  Future<void> tryUnlock(String text) async {
     text = text.trim();
     setState(() {
       _errorText = null;

lib/widgets/log_view.dart

@@ -81,10 +81,10 @@ extension on LogEvent {
   String toDisplayString() {
     var str = '# [${level.toString().split('.').last.toUpperCase()}] $title';
     if (exception != null) {
-      str += ' - ${exception.toString()}';
+      str += ' - $exception';
     }
     if (stackTrace != null) {
-      str += '\n${stackTrace.toString()}';
+      str += '\n$stackTrace';
     }
     return str;
   }

lib/widgets/matrix.dart

@@ -342,7 +342,7 @@ class MatrixState extends State<Matrix> with WidgetsBindingObserver {
     createVoipPlugin();
   }
 
-  void createVoipPlugin() async {
+  Future<void> createVoipPlugin() async {
     if (AppSettings.experimentalVoip.value) {
       voipPlugin = null;
       return;

lib/widgets/member_actions_popup_menu_button.dart

@@ -10,7 +10,7 @@ import 'adaptive_dialogs/user_dialog.dart';
 import 'avatar.dart';
 import 'future_loading_dialog.dart';
 
-void showMemberActionsPopupMenu({
+Future<void> showMemberActionsPopupMenu({
   required BuildContext context,
   required User user,
   void Function()? onMention,

lib/widgets/mxc_image.dart

@@ -109,7 +109,7 @@ class _MxcImageState extends State<MxcImage> {
     }
   }
 
-  void _tryLoad() async {
+  Future<void> _tryLoad() async {
     if (_imageData != null) {
       return;
     }

lib/widgets/qr_code_viewer.dart

@@ -24,7 +24,7 @@ class QrCodeViewer extends StatelessWidget {
 
   const QrCodeViewer({required this.content, super.key});
 
-  void _save(BuildContext context) async {
+  Future<void> _save(BuildContext context) async {
     final imageResult = await showFutureLoadingDialog(
       context: context,
       future: () {

lib/widgets/share_scaffold_dialog.dart

@@ -48,7 +48,7 @@ class _ShareScaffoldDialogState extends State<ShareScaffoldDialog> {
     });
   }
 
-  void _forwardAction() async {
+  Future<void> _forwardAction() async {
     final roomId = selectedRoomId;
     if (roomId == null) {
       throw Exception(

lib/widgets/theme_builder.dart

@@ -41,7 +41,7 @@ class ThemeController extends State<ThemeBuilder> {
   static ThemeController of(BuildContext context) =>
       Provider.of<ThemeController>(context, listen: false);
 
-  void _loadData(_) async {
+  Future<void> _loadData(_) async {
     final preferences = _sharedPreferences ??=
         await SharedPreferences.getInstance();