Implement /update-check endpoint aligned with remote OpenAPI spec:
- Add checkForUpdates() method to LicenseClientInterface
- Add UpdateInfo DTO for update check responses
- Add ProductNotFoundException for product_not_found error
- Update local openapi.json to v0.4.0
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Create docs/client-implementation.md with full integration guide
- Document all classes: clients, DTOs, exceptions, security classes
- Add integration examples for WordPress, Laravel, Symfony
- Include best practices and troubleshooting sections
- Update README with documentation links
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
