fix: improve blockchain node RPC responses and database path consistency

- Add transaction data to RPC responses (get_block, get_blocks_range)
- Fix import_block to handle transactions parameter
- Change database paths to absolute paths for consistency
- Make dev_heartbeat.py executable

apps/blockchain-node/src/aitbc_chain/consensus/poa.py

@@ -185,6 +185,7 @@ class PoAProposer:
                         tx_hash=tx.tx_hash,
                         sender=sender,
                         recipient=recipient,
+                        payload=tx_data,
                         value=value,
                         fee=fee,
                         nonce=sender_account.nonce - 1,
@@ -237,6 +238,7 @@ class PoAProposer:
             )
             
             # Broadcast the new block
+            tx_list = [tx.content for tx in processed_txs] if processed_txs else []
             await gossip_broker.publish(
                 "blocks",
                 {
@@ -248,7 +250,8 @@ class PoAProposer:
                     "timestamp": block.timestamp.isoformat(),
                     "tx_count": block.tx_count,
                     "state_root": block.state_root,
-                }
+                    "transactions": tx_list,
+                },
             )
 
     async def _ensure_genesis_block(self) -> None:

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

@@ -124,7 +124,7 @@ class BlockchainNode:
                     chain_id = block_data.get("chain_id", settings.chain_id)
                     logger.info(f"Importing block for chain {chain_id}: {block_data.get('height')}")
                     sync = ChainSync(session_factory=session_scope, chain_id=chain_id)
-                    res = sync.import_block(block_data)
+                    res = sync.import_block(block_data, transactions=block_data.get("transactions"))
                     logger.info(f"Import result: accepted={res.accepted}, reason={res.reason}")
                 except Exception as exc:
                     logger.error(f"Error processing block from gossip: {exc}")

apps/blockchain-node/src/aitbc_chain/rpc/router.py

@@ -105,6 +105,14 @@ async def get_block(height: int) -> Dict[str, Any]:
             metrics_registry.increment("rpc_get_block_not_found_total")
             raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="block not found")
         metrics_registry.increment("rpc_get_block_success_total")
+        
+        txs = session.exec(select(Transaction).where(Transaction.block_height == height)).all()
+        tx_list = []
+        for tx in txs:
+            t = dict(tx.payload) if tx.payload else {}
+            t["tx_hash"] = tx.tx_hash
+            tx_list.append(t)
+        
     metrics_registry.observe("rpc_get_block_duration_seconds", time.perf_counter() - start)
     return {
         "height": block.height,
@@ -114,6 +122,7 @@ async def get_block(height: int) -> Dict[str, Any]:
         "timestamp": block.timestamp.isoformat(),
         "tx_count": block.tx_count,
         "state_root": block.state_root,
+        "transactions": tx_list,
     }
 
 
@@ -151,6 +160,13 @@ async def get_blocks_range(start: int, end: int) -> Dict[str, Any]:
         # Serialize blocks
         block_list = []
         for block in blocks:
+            txs = session.exec(select(Transaction).where(Transaction.block_height == block.height)).all()
+            tx_list = []
+            for tx in txs:
+                t = dict(tx.payload) if tx.payload else {}
+                t["tx_hash"] = tx.tx_hash
+                tx_list.append(t)
+            
             block_list.append({
                 "height": block.height,
                 "hash": block.hash,
@@ -159,6 +175,7 @@ async def get_blocks_range(start: int, end: int) -> Dict[str, Any]:
                 "timestamp": block.timestamp.isoformat(),
                 "tx_count": block.tx_count,
                 "state_root": block.state_root,
+                "transactions": tx_list,
             })
         
         metrics_registry.increment("rpc_get_blocks_range_success_total")