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

expense_planner/lib/main.dart

@@ -8,6 +8,8 @@ import './models/transaction.dart';
 void main() => runApp(MyApp());
 
 class MyApp extends StatelessWidget {
+  const MyApp({super.key});
+
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
@@ -38,6 +40,8 @@ class MyApp extends StatelessWidget {
 }
 
 class MyHomePage extends StatefulWidget {
+  const MyHomePage({super.key});
+
   @override
   _MyHomePageState createState() => _MyHomePageState();
 }
@@ -75,8 +79,8 @@ class _MyHomePageState extends State<MyHomePage> {
       builder: (_) {
         return GestureDetector(
           onTap: () {},
-          child: NewTransaction(_addNewTransaction),
           behavior: HitTestBehavior.opaque,
+          child: NewTransaction(_addNewTransaction),
         );
       },
     );

expense_planner/lib/widgets/chart.dart

@@ -7,7 +7,7 @@ import '../models/transaction.dart';
 class Chart extends StatelessWidget {
   final List<Transaction> recentTransactions;
 
-  Chart(this.recentTransactions);
+  const Chart(this.recentTransactions, {super.key});
 
   List<Map<String, Object>> get groupedTransactionValues {
     return List.generate(7, (index) {

expense_planner/lib/widgets/chart_bar.dart

@@ -5,13 +5,13 @@ class ChartBar extends StatelessWidget {
   final double spendingAmount;
   final double spendingPctOfTotal;
 
-  ChartBar(this.label, this.spendingAmount, this.spendingPctOfTotal);
+  const ChartBar(this.label, this.spendingAmount, this.spendingPctOfTotal, {super.key});
 
   @override
   Widget build(BuildContext context) {
     return Column(
       children: <Widget>[
-        Container(
+        SizedBox(
           height: 20,
           child: FittedBox(
             child: Text('\$${spendingAmount.toStringAsFixed(0)}'),
@@ -20,7 +20,7 @@ class ChartBar extends StatelessWidget {
         SizedBox(
           height: 4,
         ),
-        Container(
+        SizedBox(
           height: 60,
           width: 10,
           child: Stack(

expense_planner/lib/widgets/new_transaction.dart

@@ -4,7 +4,7 @@ import 'package:intl/intl.dart';
 class NewTransaction extends StatefulWidget {
   final Function addTx;
 
-  NewTransaction(this.addTx);
+  const NewTransaction(this.addTx, {super.key});
 
   @override
   _NewTransactionState createState() => _NewTransactionState();
@@ -72,7 +72,7 @@ class _NewTransactionState extends State<NewTransaction> {
               keyboardType: TextInputType.number,
               onSubmitted: (_) => _submitData(),
             ),
-            Container(
+            SizedBox(
               height: 70,
               child: Row(
                 children: <Widget>[

expense_planner/lib/widgets/transaction_list.dart

@@ -7,11 +7,11 @@ class TransactionList extends StatelessWidget {
   final List<Transaction> transactions;
   final Function deleteTx;
 
-  TransactionList(this.transactions, this.deleteTx);
+  const TransactionList(this.transactions, this.deleteTx, {super.key});
 
   @override
   Widget build(BuildContext context) {
-    return Container(
+    return SizedBox(
       height: 450,
       child: transactions.isEmpty
           ? Column(
@@ -23,7 +23,7 @@ class TransactionList extends StatelessWidget {
                 SizedBox(
                   height: 20,
                 ),
-                Container(
+                SizedBox(
                     height: 200,
                     child: Image.asset(
                       'assets/images/waiting.png',

expense_planner/lib/widgets/user_transactions.dart

@@ -5,6 +5,8 @@ import './transaction_list.dart';
 import '../models/transaction.dart';
 
 class UserTransactions extends StatefulWidget {
+  const UserTransactions({super.key});
+
   @override
   _UserTransactionsState createState() => _UserTransactionsState();
 }