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

using_listwheelscrollview/lib/roundcontainer.dart

@@ -3,8 +3,9 @@ import 'package:flutter/material.dart';
 class NewWidget extends StatelessWidget {
   final Widget l;
   final String s;
-  double radius = 8;
-  NewWidget({required this.size, required this.l, required this.s});
+  final double radius = 8;
+  const NewWidget(
+      {super.key, required this.size, required this.l, required this.s});
   final double size;
 
   @override
@@ -20,7 +21,7 @@ class NewWidget extends StatelessWidget {
           BoxShadow(
             offset: Offset(5, 5),
             blurRadius: radius,
-            color: Color(0XFF585858).withOpacity(.3),
+            color: Color(0XFF585858).withValues(alpha: .3),
           ),
         ],
       ),