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/blockchain-node/src/aitbc_chain/config.py

@@ -15,7 +15,7 @@ class ChainSettings(BaseSettings):
     rpc_bind_host: str = "127.0.0.1"
     rpc_bind_port: int = 8080
 
-    p2p_bind_host: str = "0.0.0.0"
+    p2p_bind_host: str = "127.0.0.2"
     p2p_bind_port: int = 7070
 
     proposer_id: str = "ait-devnet-proposer"