network: add hub registration, Redis persistence, and federated mesh join protocol

- Change default P2P port from 7070 to 8001 in config and .env.example
- Add redis_url configuration option for hub persistence (default: redis://localhost:6379)
- Implement DNS-based hub registration/unregistration via HTTPS API endpoints
- Add Redis persistence for hub registrations with 1-hour TTL
- Add island join request/response protocol with member list and blockchain credentials
- Add GPU marketplace tracking (offers, bids, providers) in hub manager
- Add

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

@@ -26,11 +26,11 @@ class ChainSettings(BaseSettings):
     supported_chains: str = "ait-devnet" # Comma-separated list of supported chain IDs
     db_path: Path = Path("/var/lib/aitbc/data/chain.db")
 
-    rpc_bind_host: str = "127.0.0.1"
+    rpc_bind_host: str = "0.0.0.0"
     rpc_bind_port: int = 8080
 
-    p2p_bind_host: str = "127.0.0.2"
-    p2p_bind_port: int = 7070
+    p2p_bind_host: str = "0.0.0.0"
+    p2p_bind_port: int = 8001
 
     proposer_id: str = ""
     proposer_key: Optional[str] = None
@@ -85,6 +85,9 @@ class ChainSettings(BaseSettings):
     hub_discovery_url: str = "hub.aitbc.bubuit.net"  # Hub discovery DNS
     bridge_islands: str = ""  # Comma-separated list of islands to bridge (optional)
 
+    # Redis Configuration (Hub persistence)
+    redis_url: str = "redis://localhost:6379"  # Redis connection URL
+
     # Keystore for proposer private key (future block signing)
     keystore_path: Path = Path("/var/lib/aitbc/keystore")
     keystore_password_file: Path = Path("/var/lib/aitbc/keystore/.password")