feat: add marketplace metrics, privacy features, and service registry endpoints

- Add Prometheus metrics for marketplace API throughput and error rates with new dashboard panels
- Implement confidential transaction models with encryption support and access control
- Add key management system with registration, rotation, and audit logging
- Create services and registry routers for service discovery and management
- Integrate ZK proof generation for privacy-preserving receipts
- Add metrics instru

ecosystem-certification/test-suite/README.md

@@ -0,0 +1,55 @@
+# AITBC SDK Conformance Test Suite
+
+Language-agnostic test suite for validating AITBC SDK implementations against the official API specification.
+
+## Architecture
+
+The test suite uses black-box HTTP API testing to validate SDK compliance:
+- **Mock AITBC Server**: Validates requests against OpenAPI spec
+- **Test Runners**: Docker containers for each language
+- **Test Fixtures**: JSON/YAML test cases
+- **Reporting**: Detailed compliance reports
+
+## Quick Start
+
+```bash
+# Run Bronze certification tests
+docker-compose run python-sdk bronze
+
+# Run Silver certification tests
+docker-compose run python-sdk silver
+
+# Run all tests
+docker-compose run python-sdk all
+```
+
+## Test Structure
+
+```
+test-suite/
+├── fixtures/           # Test cases (JSON/YAML)
+├── runners/           # Language-specific test runners
+├── mock-server/       # OpenAPI mock server
+├── reports/           # Test results
+└── docker-compose.yml
+```
+
+## Certification Levels
+
+### Bronze Tests
+- API compliance
+- Authentication
+- Error handling
+- Data model validation
+
+### Silver Tests
+- Performance benchmarks
+- Rate limiting
+- Retry logic
+- Async support
+
+### Gold Tests
+- Enterprise features
+- Scalability
+- Security compliance
+- SLA validation