fix(sync): resolve multi-chain gossip block propagation and sync across nodes

dev/tests/test_sync.py

@@ -0,0 +1,31 @@
+import asyncio
+import httpx
+import time
+
+async def main():
+    async with httpx.AsyncClient() as client:
+        print("Submitting transaction to aitbc (testnet)...")
+        tx_data = {
+            "type": "transfer",
+            "sender": "0xTEST_SENDER",
+            "nonce": int(time.time()),
+            "fee": 1,
+            "payload": {"amount": 100, "recipient": "0xTEST_RECIPIENT"},
+            "sig": "0xSIG"
+        }
+        resp = await client.post("http://10.1.223.93:8082/rpc/sendTx?chain_id=ait-testnet", json=tx_data)
+        print("aitbc response:", resp.status_code, resp.text)
+        
+        print("Waiting 5 seconds for gossip propagation and block proposing...")
+        await asyncio.sleep(5)
+        
+        print("Checking head on aitbc...")
+        resp = await client.get("http://10.1.223.93:8082/rpc/head?chain_id=ait-testnet")
+        print("aitbc head:", resp.status_code, resp.json())
+        
+        print("Checking head on aitbc1...")
+        resp = await client.get("http://10.1.223.40:8082/rpc/head?chain_id=ait-testnet")
+        print("aitbc1 head:", resp.status_code, resp.json())
+
+if __name__ == "__main__":
+    asyncio.run(main())