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

firebase_google_authentication/lib/Screens/InfoPage.dart

@@ -4,7 +4,7 @@ import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
 class InfoPage extends StatefulWidget {
-  const InfoPage({Key? key}) : super(key: key);
+  const InfoPage({super.key});
 
   @override
   _InfoPageState createState() => _InfoPageState();
@@ -53,7 +53,7 @@ class _InfoPageState extends State<InfoPage> {
                   height: 15,
                 ),
                 Text(
-                  user!.email ?? '',
+                  user.email ?? '',
                   style: TextStyle(fontSize: 18, fontWeight: FontWeight.w500),
                 ),
               ],