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

bmi_calculator/lib/calculator/calculate_button.dart

@@ -22,7 +22,7 @@ class CalculateButton extends StatelessWidget {
       child: TextButton(
         style: ButtonStyle(
           overlayColor:
-              MaterialStateProperty.all(Colors.white.withOpacity(0.10)),
+              WidgetStateProperty.all(Colors.white.withValues(alpha: 0.10)),
         ),
         onPressed: onTap,
         child: const Text(

bmi_calculator/lib/calculator/calculator_page.dart

@@ -5,9 +5,9 @@ import 'package:bmi_calculator/palette.dart';
 
 class CalculatorPage extends StatelessWidget {
   CalculatorPage({
-    Key? key,
+    super.key,
     required this.title,
-  }) : super(key: key);
+  });
 
   final String title;
 

bmi_calculator/lib/main.dart

@@ -13,7 +13,7 @@ void main() {
 }
 
 class MyApp extends StatelessWidget {
-  const MyApp({Key? key}) : super(key: key);
+  const MyApp({super.key});
 
   // This widget is the root of your application.
   @override