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/analysis_options.yaml

@@ -0,0 +1,23 @@
+# Lint rules for Flutter apps.
+# See https://dart.dev/guides/language/analysis-options
+include: package:flutter_lints/flutter.yaml
+
+analyzer:
+  exclude:
+    - build/**
+    - android/**
+    - ios/**
+    - web/**
+    - windows/**
+    - macos/**
+    - linux/**
+
+linter:
+  rules:
+    # Noise in small sample apps; keep the code readable.
+    avoid_print: false
+    avoid_unnecessary_containers: false
+    file_names: false
+    library_private_types_in_public_api: false
+    non_constant_identifier_names: false
+    strict_top_level_inference: false

expense_planner/android/app/src/main/AndroidManifest.xml

@@ -12,6 +12,7 @@
         android:icon="@mipmap/ic_launcher">
         <activity
             android:name="io.flutter.embedding.android.FlutterActivity"
+            android:exported="true"
             android:launchMode="singleTop"
             android:theme="@style/LaunchTheme"
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"

expense_planner/android/app/src/main/java/io/flutter/plugins/GeneratedPluginRegistrant.java

@@ -1,19 +0,0 @@
-package io.flutter.plugins;
-
-import androidx.annotation.Keep;
-import androidx.annotation.NonNull;
-import io.flutter.Log;
-
-import io.flutter.embedding.engine.FlutterEngine;
-
-/**
- * Generated file. Do not edit.
- * This file is generated by the Flutter tool based on the
- * plugins that support the Android platform.
- */
-@Keep
-public final class GeneratedPluginRegistrant {
-  private static final String TAG = "GeneratedPluginRegistrant";
-  public static void registerWith(@NonNull FlutterEngine flutterEngine) {
-  }
-}

expense_planner/ios/Runner/GeneratedPluginRegistrant.h

@@ -1,19 +0,0 @@
-//
-//  Generated file. Do not edit.
-//
-
-// clang-format off
-
-#ifndef GeneratedPluginRegistrant_h
-#define GeneratedPluginRegistrant_h
-
-#import <Flutter/Flutter.h>
-
-NS_ASSUME_NONNULL_BEGIN
-
-@interface GeneratedPluginRegistrant : NSObject
-+ (void)registerWithRegistry:(NSObject<FlutterPluginRegistry>*)registry;
-@end
-
-NS_ASSUME_NONNULL_END
-#endif /* GeneratedPluginRegistrant_h */

expense_planner/ios/Runner/GeneratedPluginRegistrant.m

@@ -1,14 +0,0 @@
-//
-//  Generated file. Do not edit.
-//
-
-// clang-format off
-
-#import "GeneratedPluginRegistrant.h"
-
-@implementation GeneratedPluginRegistrant
-
-+ (void)registerWithRegistry:(NSObject<FlutterPluginRegistry>*)registry {
-}
-
-@end

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();
 }

expense_planner/pubspec.yaml

@@ -28,6 +28,7 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
+  flutter_lints: ^6.0.0
 
 
 # For information on the generic Dart part of this file, see the