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

apps/coordinator-api/pyproject.toml

@@ -21,6 +21,7 @@ python-dotenv = "^1.0.1"
 slowapi = "^0.1.8"
 orjson = "^3.10.0"
 gunicorn = "^22.0.0"
+prometheus-client = "^0.19.0"
 aitbc-crypto = {path = "../../packages/py/aitbc-crypto"}
 
 [tool.poetry.group.dev.dependencies]