docs: add comprehensive CONTRIBUTING.md for maintainers

- Include dart pub publish --dry-run workflow information
- Document melos-based development setup and commands
- Cover code generation, formatting, and testing procedures
- Provide publishing checklist and version management guide
- Include platform-specific testing guidelines
- Document CI workflows and common troubleshooting
- Preserve maintainer knowledge previously in setup docs

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: ened

CONTRIBUTING.md

@@ -0,0 +1,208 @@
+# Contributing to Flutter Workmanager
+
+Thank you for your interest in contributing to Flutter Workmanager! This guide will help you get started.
+
+## Development Setup
+
+### Prerequisites
+- Flutter SDK (latest stable version)
+- Android Studio / Xcode for platform-specific development
+- Melos for monorepo management
+
+### Getting Started
+
+1. Fork and clone the repository
+2. Install melos globally: `dart pub global activate melos`
+3. Bootstrap the workspace: `melos bootstrap`
+4. Run tests: `melos run test`
+
+## Project Structure
+
+This is a federated plugin with the following packages:
+- `workmanager/` - Main plugin package
+- `workmanager_android/` - Android implementation
+- `workmanager_apple/` - iOS/macOS implementation  
+- `workmanager_platform_interface/` - Shared interface
+- `example/` - Demo application
+
+## Development Workflow
+
+### Making Changes
+
+1. Create a feature branch: `git checkout -b feature/your-feature`
+2. Make your changes
+3. Run formatting: `melos run format`
+4. Run analysis: `melos run analyze` 
+5. Run tests: `melos run test`
+6. Test on example app: `cd example && flutter run`
+
+### Code Generation
+
+If you modify the Pigeon API definition in `workmanager_platform_interface/pigeons/workmanager_api.dart`:
+
+```bash
+# Regenerate Pigeon files
+melos run generate:pigeon
+```
+
+**Important**: Never manually edit generated `*.g.*` files.
+
+### Code Formatting
+
+The project uses specific formatting rules:
+
+- **Dart**: Use `dart format` (configured to exclude generated files)
+- **Kotlin**: Use `ktlint -F .` in root folder  
+- **Swift**: Use SwiftLint for formatting
+
+Generated files are automatically excluded from formatting checks.
+
+## Testing
+
+### Running Tests
+
+```bash
+# All tests
+melos run test
+
+# Specific package tests
+cd workmanager_android && flutter test
+cd workmanager_apple && flutter test
+
+# Native tests
+cd example/android && ./gradlew :workmanager_android:test
+cd example/ios && xcodebuild test -workspace Runner.xcworkspace -scheme Runner
+```
+
+### Integration Tests
+
+```bash
+# iOS integration tests
+melos run test:drive_ios
+
+# Android integration tests  
+melos run test:drive_android
+```
+
+### Example App Testing
+
+Always build the example app before completing your changes:
+
+```bash
+cd example
+flutter build apk --debug
+flutter build ios --debug --no-codesign
+```
+
+## Platform-Specific Guidelines
+
+### Android
+- Follow Android WorkManager best practices
+- Test on various Android API levels
+- Ensure background task constraints work properly
+
+### iOS
+- Test both Background Fetch and BGTaskScheduler APIs
+- Verify 30-second execution limits are respected
+- Test on physical devices (background tasks don't work in simulator)
+
+## Publishing (Maintainers Only)
+
+### Pre-publish Checklist
+
+Before publishing any package, run the dry-run validation:
+
+```bash
+# Validate all packages are ready for publishing
+melos run publish:dry-run
+
+# Or for individual packages:
+cd workmanager && dart pub publish --dry-run
+cd workmanager_android && dart pub publish --dry-run  
+cd workmanager_apple && dart pub publish --dry-run
+cd workmanager_platform_interface && dart pub publish --dry-run
+```
+
+This validates that:
+- All dependencies are correctly specified
+- No uncommitted changes exist
+- Package follows pub.dev guidelines
+- All required files are included
+
+### Version Management
+
+Use melos for coordinated version bumps:
+
+```bash
+# Bump versions across related packages
+melos version
+```
+
+### Publishing Process
+
+1. Ensure all tests pass: `melos run test`
+2. Run dry-run validation: `melos run publish:dry-run`
+3. Update CHANGELOGs for all modified packages
+4. Create release PR with version bumps
+5. After merge, tag release: `git tag v0.x.x`
+6. Publish packages: `melos publish --no-dry-run`
+
+## Documentation
+
+### Updating Documentation
+
+- **API docs**: Documented inline in Dart code
+- **User guides**: Located in `docs/` directory using docs.page
+- **Setup guides**: Integrated into quickstart documentation
+
+### Documentation Structure
+
+- `docs/index.mdx` - Overview and features
+- `docs/quickstart.mdx` - Installation and basic setup
+- `docs/customization.mdx` - Advanced configuration
+- `docs/debugging.mdx` - Troubleshooting guide
+
+### Testing Documentation
+
+Test documentation changes locally:
+1. Push changes to a branch
+2. View at: `https://docs.page/fluttercommunity/flutter_workmanager~your-branch`
+
+## GitHub Actions
+
+The project uses several CI workflows:
+
+- **Format** (`.github/workflows/format.yml`): Code formatting checks
+- **Analysis** (`.github/workflows/analysis.yml`): Package analysis and dry-run validation  
+- **Test** (`.github/workflows/test.yml`): Unit tests, native tests, integration tests
+
+All checks must pass before merging PRs.
+
+## Common Issues
+
+### Generated Files
+
+If you see formatting or analysis errors in generated files:
+- Never manually edit `*.g.*` files
+- Use `melos run generate:pigeon` to regenerate
+- Generated files are excluded from formatting by design
+
+### CI Failures
+
+**Package analysis failures**: Usually caused by uncommitted changes or missing dependencies
+**Format failures**: Run `melos run format` locally first
+**Test failures**: Ensure all tests pass locally with `melos run test`
+
+## Getting Help
+
+- **Bug reports**: [GitHub Issues](https://github.com/fluttercommunity/flutter_workmanager/issues)
+- **Questions**: [GitHub Discussions](https://github.com/fluttercommunity/flutter_workmanager/discussions)
+- **Documentation**: [docs.page](https://docs.page/fluttercommunity/flutter_workmanager)
+
+## Code of Conduct
+
+This project follows the [Flutter Community Code of Conduct](https://github.com/fluttercommunity/community/blob/main/CODE_OF_CONDUCT.md).
+
+## License
+
+By contributing to Flutter Workmanager, you agree that your contributions will be licensed under the [MIT License](LICENSE).