docs(annotations): improve API documentation and usage example

- Add detailed English doc comments for all main annotations (inject, injectable, instance, provide, scope, etc)
- Add fully documented example/example.dart illustrating real-world DI scenario
- Clarify stub sections (Module class, generated mixins)
- Aligns package with pub.dev quality and best practice requirements

No breaking changes.

cherrypick_annotations/example/example.dart

@@ -0,0 +1,111 @@
+// ignore: dangling_library_doc_comments
+/// Example using cherrypick_annotations together with cherrypick (core) and cherrypick_generator.
+
+///
+/// Steps to use this example:
+/// 1. Make sure your example/pubspec.yaml contains:
+///     - cherrypick_annotations (this package)
+///     - cherrypick (core DI engine)
+///     - cherrypick_generator (as a dev_dependency)
+///     - build_runner (as a dev_dependency)
+/// 2. Run code generation to produce DI injectors and mixins:
+///    ```sh
+///    dart run build_runner build
+///    ```
+/// 3. The `_$ApiScreen` mixin will be generated automatically.
+/// 4. In your app/bootstrap code, install modules and use the generated features.
+///
+/// See documentation and advanced details at:
+/// https://pub.dev/packages/cherrypick_annotations
+
+import 'package:cherrypick_annotations/cherrypick_annotations.dart';
+// In a real project, use this import:
+// import 'package:cherrypick/cherrypick.dart';
+
+// Temporary stub for demonstration purposes only.
+// In real usage, import 'Module' from `package:cherrypick/cherrypick.dart`.
+class Module {}
+
+/// This mixin is a stub for documentation and IDE hints only.
+/// In a real project, it will be generated by cherrypick_generator after running build_runner.
+///
+/// Do not implement or edit this by hand!
+mixin _$ApiScreen {}
+
+/// Example UI/service class with dependencies to be injected.
+///
+/// The [@injectable] annotation tells the generator to create an injector mixin for this class.
+/// Fields marked with [@inject] will be automatically filled by the code generator (using DI).
+@injectable()
+class ApiScreen with _$ApiScreen {
+  /// The default (main) implementation of the API service.
+  @inject()
+  late final ApiService apiService;
+
+  /// An alternate API (mock) implementation, injected by name using @named.
+  @inject()
+  @named('mock')
+  late final ApiService mockApiService;
+
+  /// Logger injected from another scope (e.g., global singleton).
+  @inject()
+  @scope('global')
+  late final Logger logger;
+}
+
+/// Example DI module using CherryPick annotations.
+///
+/// The [@module] annotation tells the generator to treat this class as a source of bindings.
+/// Methods annotated with [@singleton], [@named], [@provide], [@instance] will be registered into the DI container.
+@module()
+abstract class AppModule extends Module {
+  /// Global singleton logger available throughout the app.
+  @singleton()
+  Logger provideLogger() => Logger();
+
+  /// Main API implementation, identified with the name 'main'.
+  @named('main')
+  ApiService createApi() => ApiService();
+
+  /// Mock API implementation, identified as 'mock'.
+  @named('mock')
+  ApiService createMockApi() => MockApiService();
+
+  /// UserManager is created with runtime parameters, such as per-user session.
+  @provide()
+  UserManager createManager(@params() Map<String, dynamic> runtimeParams) {
+    return UserManager(runtimeParams['id'] as String);
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Example implementations for demonstration only.
+// In a real project, these would contain application/service logic.
+
+/// The main API service.
+class ApiService {}
+
+/// A mock API implementation (for development or testing).
+class MockApiService extends ApiService {}
+
+/// Manages user operations, created using dynamic (runtime) parameters.
+class UserManager {
+  final String id;
+  UserManager(this.id);
+}
+
+/// Global logger service.
+class Logger {}
+
+void main() {
+  // After running code generation, injectors and mixins will be ready to use.
+  // Example integration (pseudo-code):
+  //
+  // import 'package:cherrypick/cherrypick.dart';
+  //
+  // final scope = CherryPick.openRootScope()..installModules([$AppModule()]);
+  // final screen = ApiScreen()..injectFields();
+  // print(screen.apiService); // <-- injected!
+  //
+  // This main() is provided for reference only.
+}

cherrypick_annotations/lib/cherrypick_annotations.dart

@@ -1,5 +1,3 @@
-library;
-
 //
 // Copyright 2021 Sergey Penkovsky (sergey.penkovsky@gmail.com)
 // Licensed under the Apache License, Version 2.0 (the "License");
@@ -13,6 +11,24 @@ library;
 // limitations under the License.
 //
 
+/// Annotations for use with the CherryPick dependency injection generator.
+///
+/// These annotations are used on classes, methods, fields or parameters to
+/// describe how they should participate in dependency injection.
+/// See: https://pub.dev/packages/cherrypick
+///
+/// Example:
+/// ```dart
+/// import 'package:cherrypick_annotations/cherrypick_annotations.dart';
+///
+/// @injectable()
+/// class MyService {
+///   @inject()
+///   late final Logger logger;
+/// }
+/// ```
+library;
+
 export 'src/module.dart';
 export 'src/provide.dart';
 export 'src/instance.dart';

cherrypick_annotations/lib/src/inject.dart

@@ -38,5 +38,6 @@ import 'package:meta/meta.dart';
 /// ```
 @experimental
 final class inject {
+  /// Creates an [inject] annotation for field injection.
   const inject();
 }

cherrypick_annotations/lib/src/injectable.dart

@@ -39,5 +39,6 @@ import 'package:meta/meta.dart';
 /// After running the generator, the mixin (`_\$ProfileScreen`) will be available to help auto-inject all [@inject] fields in your widget/service/controller.
 @experimental
 final class injectable {
+  /// Creates an [injectable] annotation for classes.
   const injectable();
 }

cherrypick_annotations/lib/src/instance.dart

@@ -45,5 +45,6 @@ import 'package:meta/meta.dart';
 /// See also: [@singleton]
 @experimental
 final class instance {
+  /// Creates an [instance] annotation for classes or providers.
   const instance();
 }

cherrypick_annotations/lib/src/provide.dart

@@ -39,6 +39,6 @@ import 'package:meta/meta.dart';
 /// See also: [@singleton], [@instance], [@params], [@named]
 @experimental
 final class provide {
-  /// Creates a [provide] annotation.
+  /// Creates a [provide] annotation for marking provider methods/classes in DI modules.
   const provide();
 }

cherrypick_annotations/lib/src/scope.dart

@@ -49,5 +49,7 @@ import 'package:meta/meta.dart';
 final class scope {
   /// The name/key of the DI scope from which to resolve this dependency.
   final String? name;
+
+  /// Creates a [scope] annotation specifying which DI scope to use for the dependency resolution.
   const scope(this.name);
 }