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

getx_counter_app/analysis_options.yaml

@@ -1,12 +1,7 @@
-# This file configures the analyzer, which statically analyzes Dart code to
-# check for errors, warnings, and lints.
-#
-# The issues identified by the analyzer are surfaced in the UI of Dart-enabled
-# IDEs (https://dart.dev/tools#ides-and-editors). The analyzer can also be
-# invoked from the command line by running `flutter analyze`.
+# Lint rules for Flutter apps.
+# See https://dart.dev/guides/language/analysis-options
+include: package:flutter_lints/flutter.yaml
 
-# The following line activates a set of recommended lints for Flutter apps,
-# packages, and plugins designed to encourage good coding practices.
 analyzer:
   exclude:
     - build/**
@@ -16,23 +11,13 @@ analyzer:
     - windows/**
     - macos/**
     - linux/**
-include: package:flutter_lints/flutter.yaml
 
 linter:
-  # The lint rules applied to this project can be customized in the
-  # section below to disable rules from the `package:flutter_lints/flutter.yaml`
-  # included above or to enable additional rules. A list of all available lints
-  # and their documentation is published at
-  # https://dart-lang.github.io/linter/lints/index.html.
-  #
-  # Instead of disabling a lint rule for the entire project in the
-  # section below, it can also be suppressed for a single line of code
-  # or a specific dart file by using the `// ignore: name_of_lint` and
-  # `// ignore_for_file: name_of_lint` syntax on the line or in the file
-  # producing the lint.
   rules:
-    # avoid_print: false  # Uncomment to disable the `avoid_print` rule
-    # prefer_single_quotes: true  # Uncomment to enable the `prefer_single_quotes` rule
-
-# Additional information about this file can be found at
-# https://dart.dev/guides/language/analysis-options
+    # 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

getx_counter_app/android/app/build.gradle.kts

@@ -6,7 +6,7 @@ plugins {
 }
 
 android {
-    namespace = "com.example.getx_counter_app"
+    namespace = "github.nisrulz.getx_counter_app"
     compileSdk = flutter.compileSdkVersion
     ndkVersion = flutter.ndkVersion
 
@@ -16,7 +16,7 @@ android {
     }
 
     defaultConfig {
-        applicationId = "com.example.getx_counter_app"
+        applicationId = "github.nisrulz.getx_counter_app"
         minSdk = flutter.minSdkVersion
         targetSdk = flutter.targetSdkVersion
         versionCode = flutter.versionCode

getx_counter_app/android/app/src/debug/AndroidManifest.xml

@@ -1,5 +1,4 @@
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.example.getx_counter_app">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
     <!-- Flutter needs it to communicate with the running application
          to allow setting breakpoints, to provide hot reload, etc.
     -->

getx_counter_app/android/app/src/profile/AndroidManifest.xml

@@ -1,5 +1,4 @@
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.example.getx_counter_app">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
     <!-- Flutter needs it to communicate with the running application
          to allow setting breakpoints, to provide hot reload, etc.
     -->

getx_counter_app/lib/main.dart

@@ -7,7 +7,7 @@ void main() {
 }
 
 class MyApp extends StatelessWidget {
-  const MyApp({Key? key}) : super(key: key);
+  const MyApp({super.key});
 
   @override
   Widget build(BuildContext context) {
@@ -22,12 +22,12 @@ class MyApp extends StatelessWidget {
 }
 
 class MyHomePage extends StatelessWidget {
-  const MyHomePage({Key? key}) : super(key: key);
+  const MyHomePage({super.key});
 
   @override
   Widget build(BuildContext context) {
     // create variable that hold out number with .obs parameter (.obs comes from getx state management)
-    var _counter = 0.obs;
+    var counter = 0.obs;
     return Scaffold(
         appBar: AppBar(
           title: const Text("Counter app with Getx (Get) state management"),
@@ -43,7 +43,7 @@ class MyHomePage extends StatelessWidget {
               // in get (getx) we must ue Obx for the widget that we want to change like setState in statefull widget\
               Obx(() => Text(
                     // we can show our variable by call .value method
-                    '${_counter.value}',
+                    '${counter.value}',
                     style: Theme.of(context).textTheme.headlineSmall,
                   )),
             ],
@@ -51,7 +51,7 @@ class MyHomePage extends StatelessWidget {
         ),
         floatingActionButton: FloatingActionButton(
           // we can plus or everything that we want by add .value method to our obs variable
-          onPressed: () => _counter.value++,
+          onPressed: () => counter.value++,
           tooltip: 'Increment',
           child: const Icon(Icons.add),
         ));