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

analytics_integration/analysis_options.yaml

@@ -0,0 +1,23 @@
+# Lint rules for Flutter apps.
+# See https://dart.dev/guides/language/analysis-options
+include: package:flutter_lints/flutter.yaml
+
+analyzer:
+  exclude:
+    - build/**
+    - android/**
+    - ios/**
+    - web/**
+    - windows/**
+    - macos/**
+    - linux/**
+
+linter:
+  rules:
+    # 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

analytics_integration/android/app/src/main/AndroidManifest.xml

@@ -10,6 +10,7 @@
         android:icon="@mipmap/ic_launcher">
         <activity
             android:name="io.flutter.embedding.android.FlutterActivity"
+            android:exported="true"
             android:launchMode="singleTop"
             android:theme="@style/LaunchTheme"
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"

analytics_integration/lib/main.dart

@@ -21,6 +21,8 @@ class FlutterAnalyticsApp extends StatelessWidget {
   static FirebaseAnalyticsObserver observer =
       FirebaseAnalyticsObserver(analytics: analytics);
 
+  const FlutterAnalyticsApp({super.key});
+
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
@@ -48,7 +50,7 @@ class FlutterAnalyticsHome extends StatefulWidget {
   final FirebaseAnalytics analytics;
   final FirebaseAnalyticsObserver observer;
 
-  FlutterAnalyticsHome({
+  const FlutterAnalyticsHome({
     super.key,
     required this.title,
     required this.analytics,

analytics_integration/lib/single_item_tile.dart

@@ -7,7 +7,7 @@ class SingleItemTile extends StatefulWidget {
   final double quantity;
   final FirebaseAnalytics analytics;
 
-  SingleItemTile({
+  const SingleItemTile({super.key, 
     required this.itemName,
     required this.price,
     required this.quantity,
@@ -76,7 +76,7 @@ class _SingleItemTileState extends State<SingleItemTile> {
                       ),
                     ),
                     Text(
-                      widget.quantity.toString() + ' kg',
+                      '${widget.quantity} kg',
                       style: TextStyle(
                         color: Colors.grey,
                         fontSize: 12,

analytics_integration/pubspec.yaml

@@ -20,6 +20,7 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
+  flutter_lints: ^6.0.0
 
 
 flutter: