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

biometrics/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

biometrics/android/app/build.gradle.kts

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

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

@@ -1,5 +1,4 @@
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="studio.sdev.biometrics">
+<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.
     -->

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

@@ -1,5 +1,4 @@
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="studio.sdev.biometrics">
+<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.
     -->

biometrics/lib/main.dart

@@ -4,6 +4,8 @@ import 'package:flutter/material.dart';
 void main() => runApp(Biometrics());
 
 class Biometrics extends StatelessWidget {
+  const Biometrics({super.key});
+
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
@@ -17,6 +19,8 @@ class Biometrics extends StatelessWidget {
 }
 
 class Home extends StatefulWidget {
+  const Home({super.key});
+
   @override
   State<Home> createState() => _HomeState();
 }
@@ -72,6 +76,7 @@ class _HomeState extends State<Home> {
                         });
                       } catch (e) {
                         // ---- Verification Failed
+                        if (!context.mounted) return;
                         showDialog(
                           context: context,
                           builder: (c) => AlertDialog(