Fix RPC server startup in blockchain node service

- Modify combined_main.py to start HTTP RPC server alongside blockchain node
- Use uvicorn.Server with asyncio to run both services concurrently
- Fix shutdown code to properly stop HTTP server
- eth_getLogs endpoint now accessible at http://localhost:8006/rpc/eth_getLogs

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

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 """
 Combined blockchain node and P2P service launcher
-Runs both the main blockchain node and P2P placeholder service
+Runs both the main blockchain node, P2P placeholder service, and HTTP RPC server
 """
 
 import asyncio
@@ -14,6 +14,8 @@ sys.path.insert(0, str(Path(__file__).parent.parent))
 
 from aitbc_chain.main import BlockchainNode, _run as run_node
 from aitbc_chain.config import settings
+from aitbc_chain.app import create_app
+import uvicorn
 
 logging.basicConfig(level=logging.INFO)
 logger = logging.getLogger(__name__)
@@ -21,20 +23,35 @@ logger = logging.getLogger(__name__)
 class CombinedService:
     def __init__(self):
         self._tasks = []
+        self._http_server = None
         
     async def start(self):
-        """Start both blockchain node and P2P server"""
+        """Start both blockchain node and HTTP RPC server"""
         logger.info("Starting combined blockchain service")
         
         # Start blockchain node in background
         node_task = asyncio.create_task(run_node())
         self._tasks.append(node_task)
         
-        logger.info(f"Combined service started - Node on mainnet")
+        # Start HTTP RPC server in background
+        app = create_app()
+        config = uvicorn.Config(
+            app,
+            host="0.0.0.0",
+            port=8006,
+            log_level="info"
+        )
+        self._http_server = uvicorn.Server(config)
+        http_task = asyncio.create_task(self._http_server.serve())
+        self._tasks.append(http_task)
+        
+        logger.info("Combined service started - Node on mainnet, RPC server on port 8006")
         
         try:
-            # Wait for the node task to complete
+            # Wait for any task to complete (should not happen in normal operation)
-            await node_task
+            await asyncio.gather(*self._tasks, return_exceptions=True)
+        except KeyboardInterrupt:
+            logger.info("Received keyboard interrupt")
         finally:
             await self.stop()
     
@@ -42,6 +59,10 @@ class CombinedService:
         """Stop all services"""
         logger.info("Stopping combined blockchain service")
         
+        # Shutdown HTTP server if running
+        if self._http_server:
+            self._http_server.should_exit = True
+        
         # Cancel all tasks
         for task in self._tasks:
             if not task.done():