```

chore: remove obsolete payment architecture and integration test documentation

- Remove AITBC_PAYMENT_ARCHITECTURE.md (dual-currency system documentation)
- Remove IMPLEMENTATION_COMPLETE_SUMMARY.md (integration test completion summary)
- Remove INTEGRATION_TEST_FIXES.md (test fixes documentation)
- Remove INTEGRATION_TEST_UPDATES.md (real features implementation notes)
- Remove PAYMENT_INTEGRATION_COMPLETE.md (wallet-coordinator integration docs)
- Remove WALLET_COORDINATOR_INTEGRATION.md (payment

apps/blockchain-node/src/aitbc_chain/gossip/relay.py

@@ -0,0 +1,99 @@
+#!/usr/bin/env python3
+"""
+Simple gossip relay service for blockchain nodes
+Uses Starlette Broadcast to share messages between nodes
+"""
+
+import argparse
+import asyncio
+import logging
+from typing import Any, Dict
+
+from starlette.applications import Starlette
+from starlette.broadcast import Broadcast
+from starlette.middleware import Middleware
+from starlette.middleware.cors import CORSMiddleware
+from starlette.routing import Route, WebSocketRoute
+from starlette.websockets import WebSocket
+import uvicorn
+
+# Setup logging
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+# Global broadcast instance
+broadcast = Broadcast("memory://")
+
+
+async def gossip_endpoint(request):
+    """HTTP endpoint for publishing gossip messages"""
+    try:
+        data = await request.json()
+        channel = data.get("channel", "blockchain")
+        message = data.get("message")
+        
+        if message:
+            await broadcast.publish(channel, message)
+            logger.info(f"Published to {channel}: {str(message)[:50]}...")
+            
+            return {"status": "published", "channel": channel}
+        else:
+            return {"status": "error", "message": "No message provided"}
+    except Exception as e:
+        logger.error(f"Error publishing: {e}")
+        return {"status": "error", "message": str(e)}
+
+
+async def websocket_endpoint(websocket: WebSocket):
+    """WebSocket endpoint for real-time gossip"""
+    await websocket.accept()
+    
+    # Get channel from query params
+    channel = websocket.query_params.get("channel", "blockchain")
+    logger.info(f"WebSocket connected to channel: {channel}")
+    
+    try:
+        async with broadcast.subscribe(channel) as subscriber:
+            async for message in subscriber:
+                await websocket.send_text(message)
+    except Exception as e:
+        logger.error(f"WebSocket error: {e}")
+    finally:
+        logger.info("WebSocket disconnected")
+
+
+def create_app() -> Starlette:
+    """Create the Starlette application"""
+    routes = [
+        Route("/gossip", gossip_endpoint, methods=["POST"]),
+        WebSocketRoute("/ws", websocket_endpoint),
+    ]
+    
+    middleware = [
+        Middleware(CORSMiddleware, allow_origins=["*"], allow_methods=["*"])
+    ]
+    
+    return Starlette(routes=routes, middleware=middleware)
+
+
+def main():
+    parser = argparse.ArgumentParser(description="AITBC Gossip Relay")
+    parser.add_argument("--host", default="127.0.0.1", help="Bind host")
+    parser.add_argument("--port", type=int, default=7070, help="Bind port")
+    parser.add_argument("--log-level", default="info", help="Log level")
+    
+    args = parser.parse_args()
+    
+    logger.info(f"Starting gossip relay on {args.host}:{args.port}")
+    
+    app = create_app()
+    uvicorn.run(
+        app,
+        host=args.host,
+        port=args.port,
+        log_level=args.log_level
+    )
+
+
+if __name__ == "__main__":
+    main()