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

save_data_locally_with_sqlite/lib/database/local_database.dart

@@ -15,17 +15,18 @@ class LocalDatabase {
   static final LocalDatabase instance = LocalDatabase._privateConstructor();
 
   Future<Database?> get database async {
-    if (_database != null)
+    if (_database != null) {
       return _database; //if database already present it return the database else create a new one then return it
+    }
     _database = await _initDatabase();
     return _database;
   }
 
-  _initDatabase() async {
+  Future<Database> _initDatabase() async {
     Directory documentsDirectory = await getApplicationDocumentsDirectory();
-    String path = join(documentsDirectory.path, '$_databaseName');
+    String path = join(documentsDirectory.path, _databaseName);
     return await openDatabase(path, version: _databaseVersion,
-        onCreate: (db, int) async {
+        onCreate: (db, version) async {
       await db.execute('''
               CREATE TABLE data (
               datetime TEXT,