Initialize composer project for WooCommerce Licensed Product Client

- Set up composer.json with package metadata and PSR-4 autoloading
- Add symfony/http-client ^7.0 as HTTP client dependency
- Create project structure (src/, tests/, tmp/)
- Add README.md with project overview
- Add CHANGELOG.md to track version history
- Add .gitignore for vendor and cache files
- Include OpenAPI specification in tmp/openapi.json

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

README.md

@@ -0,0 +1,49 @@
+# WooCommerce Licensed Product Client
+
+A PHP client library for the WooCommerce Licensed Product Plugin REST API. Activate, validate, and check the status of software licenses.
+
+## Requirements
+
+- PHP 8.3 or higher
+- Composer
+
+## Installation
+
+```bash
+composer require magdev/wc-licensed-product-client
+```
+
+## Features
+
+- Easy integration in licensed software packages
+- License validation against domains
+- License activation on domains
+- License status checking
+- Built on Symfony HttpClient
+
+## API Endpoints
+
+This client interacts with the following WooCommerce Licensed Product API endpoints:
+
+- **POST /validate** - Validate a license key for a specific domain
+- **POST /status** - Get detailed license status information
+- **POST /activate** - Activate a license on a domain
+
+## Usage
+
+Coming soon in future versions.
+
+## License
+
+GPL-2.0-or-later
+
+## Author
+
+Marco Graetsch
+
+- Website: <https://src.bundespruefstelle.ch/magdev>
+- Email: <magdev3.0@gmail.com>
+
+## Contributing
+
+Issues and pull requests are welcome at <https://src.bundespruefstelle.ch/magdev/wc-licensed-product-client/issues>