added controller scope and extension for context

lib/model/extensions/controller_context.dart

@@ -0,0 +1,9 @@
+import 'package:flutter/material.dart';
+
+import '../../service/controller_scope.dart';
+
+extension ControllerContext on BuildContext {
+  T controller<T extends ChangeNotifier>() {
+    return ControllerScope.of<T>(this);
+  }
+}

lib/service/controller_scope.dart

@@ -0,0 +1,18 @@
+import 'package:flutter/widgets.dart';
+
+class ControllerScope<T extends ChangeNotifier> extends InheritedNotifier<T> {
+  const ControllerScope({
+    super.key,
+    required T controller,
+    required super.child,
+  }) : super(notifier: controller);
+
+  static T of<T extends ChangeNotifier>(BuildContext context) {
+    final scope = context
+        .dependOnInheritedWidgetOfExactType<ControllerScope<T>>();
+
+    assert(scope != null, 'No ControllerScope<$T> found in context');
+
+    return scope!.notifier!;
+  }
+}