refactor: standardize Dart and Android config across all 54 apps

- Bump all apps to sdk >=3.0.0 <4.0.0 and add flutter_lints + a shared
  analysis_options.yaml to every app (flutter analyze is now green repo-wide)
- Fix real compile errors in firebase_google_authentication and image_editor,
  plus deprecated APIs (Matrix4, SvgPicture.color, textScaleFactor),
  missing async 'mounted' guards, and misc lints via dart fix + manual fixes
- Align pubspec 'name' with each folder and Android namespace/applicationId
  with the documented github.nisrulz.* convention
- Convert bmi_calculator from a legacy Flutter module to a standard app
  with a proper android/ scaffold; fix missing android:exported in launcher
  manifests across 22 apps so all Android builds pass
- Untrack generated build files (GeneratedPluginRegistrant,
  .flutter-plugins-dependencies) and ignore them

todo_list_using_provider/lib/widgets/add_button.dart

@@ -5,6 +5,8 @@ import '../models/todo.dart';
 import '../notifiers/todo_list.dart';
 
 class AddButton extends StatelessWidget {
+  const AddButton({super.key});
+
   @override
   Widget build(BuildContext context) {
     final todoList = Provider.of<TodoList>(context, listen: false);
@@ -13,7 +15,7 @@ class AddButton extends StatelessWidget {
     return FloatingActionButton(
       onPressed: () {
         todoList.add(
-          new Todo(id: '${todoList.list.length}', title: 'tituloTodo${todoList.list.length}')
+          Todo(id: '${todoList.list.length}', title: 'tituloTodo${todoList.list.length}')
         );
       },
       tooltip: 'Increment',

todo_list_using_provider/lib/widgets/todo_list_item_display.dart

@@ -4,6 +4,8 @@ import 'package:provider/provider.dart';
 import '../models/todo.dart';
 
 class TodoListItemDisplay extends StatelessWidget {
+  const TodoListItemDisplay({super.key});
+
   @override
   Widget build(BuildContext context) {
     print('rebuilding Todo List Item Display');

todo_list_using_provider/lib/widgets/todo_list_item_toggle_button.dart

@@ -4,6 +4,8 @@ import 'package:provider/provider.dart';
 import '../models/todo.dart';
 
 class TodoListItemToggleButton extends StatelessWidget {
+  const TodoListItemToggleButton({super.key});
+
   @override
   Widget build(BuildContext context) {
     print('build Toggle Item Button');

todo_list_using_provider/lib/widgets/todo_list_item_wdt.dart

@@ -5,11 +5,13 @@ import 'todo_list_item_toggle_button.dart';
 
 
 class TodoListItemWdt extends StatelessWidget {
+  const TodoListItemWdt({super.key});
+
   @override
   Widget build(BuildContext context) {
     print('rebuilding ToDo List Item: ');
 
-    return new Row(
+    return Row(
       mainAxisAlignment: MainAxisAlignment.spaceAround,
       children: [
         TodoListItemDisplay(),

todo_list_using_provider/lib/widgets/todo_list_wdt.dart

@@ -6,6 +6,8 @@ import '../notifiers/todo_list.dart';
 import '../widgets/todo_list_item_wdt.dart';
 
 class TodoListWdt extends StatelessWidget {
+  const TodoListWdt({super.key});
+
   @override
   Widget build(BuildContext context) {
     print('building Todo List Wdt');
@@ -20,7 +22,7 @@ class TodoListWdt extends StatelessWidget {
           itemBuilder: (context, index) {
             return ChangeNotifierProvider<Todo>(
                 create: (context) => todoList.list[index],
-                child: new TodoListItemWdt()
+                child: TodoListItemWdt()
             );
           },
         );