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/dummyMapPlugin.dart

@@ -2,6 +2,8 @@ import 'package:flutter/material.dart';
 
 /// Dummy/placeholder widget for map plugins
 class DummyMapPluginWidget extends StatelessWidget {
+  const DummyMapPluginWidget({super.key});
+
   @override
   Widget build(BuildContext context) {
     return const SizedBox();