fix: resolve 2 remaining strict analysis errors

- introPage.dart: Convert fireItems to proper static function closure
- mainDrawer.dart: Convert unreadCount int to String for Text widget

lib/markdownPage.dart

@@ -8,40 +8,40 @@ import 'globals.dart' as globals;
 import 'mainDrawer.dart';
 
 abstract class MarkdownPage extends StatefulWidget {
+
+  const MarkdownPage({super.key, required this.title, required this.route, required this.file});
   final String title;
   final Future<String> file;
   final String route;
 
-  MarkdownPage({required this.title, required this.route, required this.file});
-
   @override
   _MarkdownPageState createState() =>
-      _MarkdownPageState(title: this.title, file: this.file, route: this.route);
+      _MarkdownPageState(title: title, file: file, route: route);
 }
 
 class _MarkdownPageState extends State<MarkdownPage> {
-  final String title;
-  final String route;
-  final Future<String> file;
-  String pageData = "";
 
   _MarkdownPageState(
       {required this.title, required this.file, required this.route});
+  final String title;
+  final String route;
+  final Future<String> file;
+  String pageData = '';
 
   @override
   Widget build(BuildContext context) {
-    this.file.then((fileSync) {
+    file.then((String fileSync) {
       rootBundle
           .loadString(fileSync, cache: !globals.isDevelopment)
-          .then((pageData) {
+          .then((String pageData) {
         setState(() {
           this.pageData = pageData;
         });
       });
     });
-    return new Scaffold(
-        appBar: new AppBar(title: new Text(title ?? '')),
-        drawer: new MainDrawer(context, route),
-        body: new Markdown(data: pageData));
+    return Scaffold(
+        appBar: AppBar(title: Text(title ?? '')),
+        drawer: MainDrawer(context, route),
+        body: Markdown(data: pageData));
   }
 }